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Sample records for 8-anilino-1-naphthalene sulfonate ans

  1. ANS complex of St John’s wort PR-10 protein with 28 copies in the asymmetric unit: a fiendish combination of pseudosymmetry with tetartohedral twinning

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-04-01

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from H. perforatum, was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The asymmetric unit of the tetartohedrally twinned crystal contains 28 copies of the protein arranged in columns with noncrystallographic sevenfold translational symmetry and with additional pseudotetragonal rotational NCS. Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John’s wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.

  2. Unfolding and refolding of leucoagglutinin (PHA-L), an oligomeric lectin from kidney beans (Phaseolus vulgaris).

    PubMed

    Biswas, Shyamasri; Kayastha, Arvind M

    2004-09-01

    The unfolding and refolding of Phaseolus vulgaris Leucoagglutinin, a homotetrameric legume lectin, was studied at pH 2.5 and 7.2 using fluorescence, far- and near-UV circular dichroism (CD) spectroscopy, 8-anilino-1-naphthalene sulfonate (ANS) binding and FPLC techniques. This protein was found to refold even at pH 2.5 and also exhibited high refolding yield around 60% at pH 2.5 and 85% at pH 7.2. The refolding at pH 2.5 takes place with the formation of a dimeric intermediate. Although the hydrodynamic radius of the completely renatured protein and the dimer at pH 2.5 was found to be same, the ANS binding as well as far-UV CD spectra of the two were different. The denaturation kinetics at pH 2.5 followed single exponential pattern with the rate of denaturation being independent of protein concentration. The renaturation kinetics on the other hand was dependent on the protein concentration providing further evidence of an intermediate state during refolding. From these experiments the folding pathway of the protein at pH 2.5 was proposed.

  3. Characterization and primary specificity of an extracellular metalloproteinase from Serratia marcescens.

    PubMed

    Kim, N; Kim, S I

    1994-02-01

    An extracellular endopeptidase (proteinase) from Serratia marcescens (Serratia marcescens extracellular proteinase, EC 3.4.24.4), purified to homogeneity, was analyzed for enzyme properties. The enzyme has a polypeptide chain molecular mass of 52 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme has an optimal temperature of 40 degrees C and an optimal pH of 7.0. Enzyme activity was enhanced over two times by the addition of Ca2+ and Mg2+ ions and eliminated almost completely by the presence of 0.2% SDS. The enzyme has broad substrate specificity and contains neither cysteine nor methionine. Low homology was found between the NH2-terminal amino acid sequence of the enzyme of this study and the NH2-terminal sequence of a proteinase from another strain of S. marcescens. Chemical modification with N-bromosuccinimide, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide, and 8-anilino-1-naphthalene sulfonic acid and by photooxidation with methylene blue reduced enzyme activity considerably. The enzyme was shown to have broad peptide bond specificity judging from the contribution of 11 amino acids to the carboxyl side of the peptide bonds hydrolyzed.

  4. Unfolding and refolding of leucoagglutinin (PHA-L), an oligomeric lectin from kidney beans (Phaseolus vulgaris).

    PubMed

    Biswas, Shyamasri; Kayastha, Arvind M

    2004-09-01

    The unfolding and refolding of Phaseolus vulgaris Leucoagglutinin, a homotetrameric legume lectin, was studied at pH 2.5 and 7.2 using fluorescence, far- and near-UV circular dichroism (CD) spectroscopy, 8-anilino-1-naphthalene sulfonate (ANS) binding and FPLC techniques. This protein was found to refold even at pH 2.5 and also exhibited high refolding yield around 60% at pH 2.5 and 85% at pH 7.2. The refolding at pH 2.5 takes place with the formation of a dimeric intermediate. Although the hydrodynamic radius of the completely renatured protein and the dimer at pH 2.5 was found to be same, the ANS binding as well as far-UV CD spectra of the two were different. The denaturation kinetics at pH 2.5 followed single exponential pattern with the rate of denaturation being independent of protein concentration. The renaturation kinetics on the other hand was dependent on the protein concentration providing further evidence of an intermediate state during refolding. From these experiments the folding pathway of the protein at pH 2.5 was proposed. PMID:15342112

  5. Linking the solution viscosity of an IgG2 monoclonal antibody to its structure as a function of pH and temperature.

    PubMed

    Cheng, Weiqiang; Joshi, Sangeeta B; Jain, Nishant Kumar; He, Feng; Kerwin, Bruce A; Volkin, David B; Middaugh, C Russell

    2013-12-01

    Although the viscosity of concentrated antibody solutions has been the focus of many recent studies, less attention has been concentrated on how changes in protein structure impact viscosity. This study examines viscosity profiles of an immunoglobulin G (IgG) 2 monoclonal antibody at 150 mg/mL as a function of temperature and pH. Although the structure of the antibody at pH 4.0-7.0 was comparable at lower temperatures as measured by second derivative UV absorbance and Fourier transform infrared spectroscopy, differences in 8-anilino-1-naphthalene sulfonate (ANS) fluorescence intensity indicated small structural alterations as a function of pH. Below the structural transition onset temperature, the viscosity profiles were pH dependent and linearly correlated with fluorescence intensity, and followed semilogarithmic behavior as a function of temperature. The transitions of the viscosity profiles correlated well with the major structure transitions at a protein concentration of 150 mg/mL. The viscosity correlated particularly well with ANS fluorescence intensity at 0.2 mg/mL below and above the structural transition temperatures. These results suggest: (1) ANS can be an important measure of the overall structure and (2) hydrophobic interactions and charge-charge interactions are the two major physical factors that contribute collectively to the high viscosity of concentrated IgG solutions.

  6. ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: A fiendish combination of pseudosymmetry with tetartohedral twinning

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-03-26

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.

  7. ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: A fiendish combination of pseudosymmetry with tetartohedral twinning

    DOE PAGES

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-03-26

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packedmore » as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.« less

  8. ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: a fiendish combination of pseudosymmetry with tetartohedral twinning.

    PubMed

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J; Read, Randy J; Jaskolski, Mariusz

    2015-04-01

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.

  9. [Comparison of Physico-chemical Aspects between E. coli and Human Dihydrofolate Reductase: an Equilibrium Unfolding Study].

    PubMed

    Thapliyal, Charu; Jain, Neha; Chaudhuri, Pratima

    2015-01-01

    A protein, differing in origin, may exhibit variable physicochemical behaviour, difference in sequence homology, fold and function. Thus studying structure-function relationship of proteins from altered sources is meaningful in the sense that it may give rise to comparative aspects of their sequence-structure-function relationship. Dihydrofolate reductase is an enzyme involved in cell cycle regulation. It is a significant enzyme as.a target for developing anticancer drugs. Hence, detailed understanding of structure-function relationships of wide variants of the enzyme dihydrofolate reductase would be important for developing an inhibitor or an antagonist against the enzyme involved in the cellular developmental processes. In this communication, we have reported the comparative structure-function relationship between E. coli and human dihydrofolate reductase. The differences in the unfolding behaviour of these two proteins have been investigated to understand various properties of these two proteins like relative' stability differences and variation in conformational changes under identical denaturing conditions. The equilibrium unfolding mechanism of dihydrofolate reductase proteins using guanidine hydrochloride as a denaturant in the presence of various types of osmolytes has been monitored using loss in enzymatic activity, intrinsic tryptophan fluorescence and an extrinsic fluorophore 8-anilino-1-naphthalene-sulfonic acid as probes. It has been observed that osmolytes, such as 1M sucrose, and 30% glycerol, provided enhanced stability to both variants of dihydrofolate reductase. Their level of stabilisation has been observed to be dependent on intrinsic protein stability. It was observed that 100 mM proline does not show any 'significant stabilisation to either of dihydrofolate reductases. In the present study, it has been observed that the human protein is relatively less stable than the E.coli counterpart.

  10. Oil recovery method utilizing an alkylarylpoxyalkylene sulfonate

    SciTech Connect

    McCoy, D.R.

    1984-08-14

    An alkylarylpolyalkoxyalkylene sulfonate alone or combined with a water soluble petroleum sulfonate surfactant is dissolved in water to form an effective surfactant fluid that is stable in high salinity environments. The surfactant fluid is injected into an underground petroleum-containing reservoir in an enhanced oil recovery process.

  11. A FLUORESCENCE PROBE OF ENERGY-DEPENDENT STRUCTURE CHANGES IN FRAGMENTED MEMBRANES*

    PubMed Central

    Azzi, A.; Chance, B.; Radda, G. K.; Lee, C. P.

    1969-01-01

    The reaction of the fluorochrome, 8-anilino-1-naphthalene-sulfonic acid (ANS), with fragmented membranes from beef heart mitochondria has been studied. ANS fluorescence is found to be enhanced 25-fold on binding to the membrane fragments in the absence of energy conservation, and this enhancement is increased to 35-fold in the membrane energized by substrate plux oxygen. The fluorescence of bound ANS depends upon the energy state of the membrane fragments, as indicated by the effects of ATP, substrates of the respiratory chain, oligomycin, and uncouplers. It is concluded that the changes of ANS fluorescence indicate structural changes of the mitochondrial membrane associated with energy conservation. The time course of energization is readily followed by ANS, and has a half-time of two seconds at 26°. PMID:4307717

  12. Pyrolysis Pathways of Sulfonated Polyethylene, an Alternative Carbon Fiber Precursor

    SciTech Connect

    Younker, Jarod M; Saito, Tomonori; Hunt, Marcus A; Beste, Ariana; Naskar, Amit K

    2013-01-01

    Sulfonated polyethylene is an emerging precursor for the production of carbon fibers. Pyrolysis of sulfonated polyethylene was characterized by thermogravimetric analysis (TGA). n-heptane-4-sulfonic acid (H4S) was selected as a model compound for the study of sulfonated polyethylene. Density functional theory and conventional transition state theory were used to determine the rate constants of pyrolysis for H4S from 300-1000 K. Multiple reaction channels from two different mechanisms were explored: 1) internal five-centered elimination (Ei 5) and 2) radical chain reaction. The pyrolysis of H4S was simulated with kinetic Monte Carlo (kMC) to obtain TGA plots that compared favorably to experiment. We observed that at tem- peratures < 550 K, the radical mechanism was dominant and yielded the trans-alkene, whereas cis-alkene was formed at higher temperatures from the internal elimination. The maximum rates of % mass loss became independent of initial OH radical concentration at 440-480 K. Experimentally, the maximum % mass loss occurred from 440-460 K (heating rate dependent). Activation energies derived from the kMC-simulated TGAs of H4S (26-29 kcal/mol) agreed with experiment for sulfonated polyethylene ( 31 kcal/mol). The simulations revealed that in this region, decomposition of radical HOSO2 became competitive to H abstraction by HOSO2, making OH the carrying radical for the reaction chain. The maximum rate of % mass loss for internal elimination was observed at temperatures > 600 K. Low-scale carbonization utilizes temperatures < 620 K; thus, internal elimination will not be competitive. Ei5 elimination has been studied for sulfoxides and sulfones, but this represents the first study of internal elimination in sulfonic acids. Nonlinear Arrhenius plots were found for all bimolecular reactions. The most significant nonlinear behavior was observed for reactions where the barrier was small. For reactions with low activation barriers, nonlinearity was traced to

  13. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., sulfonated aromatic (generic name). 721.950 Section 721.950 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  14. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., sulfonated aromatic (generic name). 721.950 Section 721.950 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  15. Process for recovering 4,4 prime dihydroxydiphenyl sulfone from an isomer mixture

    SciTech Connect

    Zemlanicky, F.; Cooker, B.

    1991-03-19

    This patent describes a process for the recovery of 4,4{prime}-bisphenol sulfone from an isomer mixture comprising 4,4{prime}-bisphenol sulfone and 2,4{prime}-bisphenol sulfone. It comprises dissolving the isomer mixture in a basic aqueous solution comprising about one mole of base per mole of the mixture of 4,4{prime}-bisphenol sulfone and 2,4{prime}-bisphenol sulfone to form a basic isomer solution and adding acid to the isomer solution in an amount of from about 0.85 to 0.95 mole per mole of the 4,4{prime}-bisphenol sulfone wherein the acid is added in an amount sufficient to cause selective precipitation of crystals of 4,4{prime}-bisphenol sulfone yet in an amount less than sufficient to neutralize the isomer solution and removing the crystals of 4,4{prime}-bisphenol from the aqueous solution.

  16. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sodium salt of an...

  17. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sodium salt of an...

  18. Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium.

    PubMed

    Plancarte, A; Romero, J R; Nava, G; Reyes, H; Hernández, M

    2014-03-01

    Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 μM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 μM and its intrinsic fluorescence quenching KD = 0.7 μM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.

  19. Binding interaction of differently charged fluorescent probes with egg yolk phosphatidylcholine and the effect of β-cyclodextrin on the lipid-probe complexes: a fluorometric investigation.

    PubMed

    Kundu, Pronab; Ghosh, Saptarshi; Jana, Barnali; Chattopadhyay, Nitin

    2015-05-01

    Interaction of cationic phenosafranin (PSF), anionic 8-anilino-1-naphthalene sulfonate (ANS) and non-ionic nile red (NR) have been studied with the zwitterionic phospholipid, egg yolk L-α-phosphatidylcholine (EYPC). The study reveals discernible binding interactions of the three fluorescent probes with the EYPC lipid vesicle. Once the binding of the probes with the lipid is established, the effect of cyclic oligosaccharide, β-cyclodextrin (β-CD), on these lipid bound probes has been investigated. Different fluorometric techniques suggest that addition of β-CD to the probe-lipid complexes leads to the release of the probes from the lipid medium through the formation of probe-β-CD inclusion complexes. A competitive binding of the probes between β-cyclodextrin and the lipid is ascribed to be responsible for the effect. This provides an easy avenue for the removal of the probe molecules from the lipid environment. Extension of this work with drug molecules in cell membranes is expected to give rise to a strategy for the removal of adsorbed drugs from the cell membranes by the use of non-toxic β-cyclodextrin.

  20. Binding interaction of differently charged fluorescent probes with egg yolk phosphatidylcholine and the effect of β-cyclodextrin on the lipid-probe complexes: A fluorometric investigation

    NASA Astrophysics Data System (ADS)

    Kundu, Pronab; Ghosh, Saptarshi; Jana, Barnali; Chattopadhyay, Nitin

    2015-05-01

    Interaction of cationic phenosafranin (PSF), anionic 8-anilino-1-naphthalene sulfonate (ANS) and non-ionic nile red (NR) have been studied with the zwitterionic phospholipid, egg yolk L-α-phosphatidylcholine (EYPC). The study reveals discernible binding interactions of the three fluorescent probes with the EYPC lipid vesicle. Once the binding of the probes with the lipid is established, the effect of cyclic oligosaccharide, β-cyclodextrin (β-CD), on these lipid bound probes has been investigated. Different fluorometric techniques suggest that addition of β-CD to the probe-lipid complexes leads to the release of the probes from the lipid medium through the formation of probe-β-CD inclusion complexes. A competitive binding of the probes between β-cyclodextrin and the lipid is ascribed to be responsible for the effect. This provides an easy avenue for the removal of the probe molecules from the lipid environment. Extension of this work with drug molecules in cell membranes is expected to give rise to a strategy for the removal of adsorbed drugs from the cell membranes by the use of non-toxic β-cyclodextrin.

  1. Dynamics of Saxitoxin Binding to Saxiphilin C-lobe Reveals Conformational Change

    PubMed Central

    Lewis, Penny; Fritsch, Ingrid; Gawley, Robert E.; Henry, Ralph; Kight, Alicia; Lay, Jackson O.; Liyanage, Rohana; McLachlin, Jeanne

    2008-01-01

    Thermodynamic parameters (ΔG, ΔH, ΔS, ΔCp) have been determined to evaluate the dynamics of binding of saxitoxin to the c-lobe of saxiphilin. We have developed an improved method to rapidly express and purify recombinant saxiphilin c-lobe, and fully characterized it by mass spectrometry for the first time. Surface plasmon resonance was used to characterize the interaction between saxitoxin and immobilized c-lobe. At 298K, c-lobe binds saxitoxin with KD = 1.2 nM, ΔH° = −11.7 ± 0.8 kcal/mol, and ΔS° = 1.17 ± 0.07 cal/mol·K. Analysis of ΔCp of toxin association at several temperatures suggests that hydrophobic forces contribute to the binding event. Additionally, changes in 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence upon binding to c-lobe in the presence and absence of saxitoxin support a conformational change in c-lobe upon saxitoxin binding. PMID:18023463

  2. Deciphering aggregates, prefibrillar oligomers and protofibrils of cytochrome c.

    PubMed

    Amani, Samreen; Naeem, Aabgeena

    2014-08-01

    Aggregation of protein into insoluble intracellular complexes and inclusion bodies underlies the pathogenesis of human neurodegenerative diseases. Importance of cytochrome c (cyt c) arises from its involvement in apoptosis, sequence homology and for studying molecular evolution. A systemic investigation of polyethylene glycol (PEG) and trifluoroethanol (TFE) on the conformational stability of cyt c as a model hemeprotein was made using multi-methodological approach. Cyt c exists as molten globule (MG) at 60% PEG-400 and 40% TFE as confirmed by far-UV CD, attenuated total reflection Fourier transform infrared spectroscopy, Trp environment, 8-anilino-1-naphthalene-sulfonic acid (ANS) binding and blue shift in the soret band. Q-band splitting in MG states specifies conformational changes in the hydrophobic heme-binding pocket. Aggregates were detected at 90% PEG-400 and 50% TFE as confirmed by increase thioflavin T and ANS fluorescence and shift in Congo red absorbance. Detection of prefibrils and protofibrils at 90% PEG-400 and 50% TFE was possible after 72-h incubation. Single cell gel electrophoresis of prefibrils and protofibrils showed DNA damage confirming their toxicity and potential health hazards. Scanning electron microscopy and XRD analysis confirmed prefibrillar oligomers and protofibrils of cyt c. PMID:24729012

  3. Compact acid-induced state of Clitoria ternatea agglutinin retains its biological activity.

    PubMed

    Naeem, A; Saleemuddin, M; Khan, R H

    2009-10-01

    The effects of pH on Clitoria ternatea agglutinin (CTA) were studied by spectroscopy, size-exclusion chromatography, and by measuring carbohydrate specificity. At pH 2.6, CTA lacks well-defined tertiary structure, as seen by fluorescence and near-UV CD spectra. Far-UV CD spectra show retention of 50% native-like secondary structure. The mean residue ellipticity at 217 nm plotted against pH showed a transition around pH 4.0 with loss of secondary structure leading to the formation of an acid-unfolded state. This state is relatively less denatured than the state induced by 6 M guanidine hydrochloride. With a further decrease in pH, this unfolded state regains ~75% secondary structure at pH 1.2, leading to the formation of the A-state with native-like near-UV CD spectral features. Enhanced 8-anilino-1-naphthalene-sulfonate binding was observed in A-state, indicating a "molten-globule" like conformation with exposed hydrophobic residues. Acrylamide quenching data exhibit reduced accessibility of quencher to tryptophan, suggesting a compact conformation at low pH. Size-exclusion chromatography shows the presence of a compact intermediate with hydrodynamic size corresponding to a monomer. Thermal denaturation of the native state was cooperative single-step transition and of the A-state was non-cooperative two-step transition. A-State regains 72% of the carbohydrate-binding activity. PMID:19916921

  4. A fluorescence study on the interaction of telmisartan in triblock polymers pluronic P123 and F127

    NASA Astrophysics Data System (ADS)

    Mohanty, Maneesha Esther; Rao, Vaidya Jayathirtha; Mishra, Ashok Kumar

    2014-03-01

    Telmisartan is a poorly soluble drug used in treatment of hypertension. There is a recent interest to use pluronic for improving the solubility and bioavailability of these drugs. In this study the interaction of telmisartan with P123 and F127 has been carried out using steady state and time dependent fluorescence study. Quenching of telmisartan fluorescence by potassium iodide is controlled by interactions arising from collisions and complex formation. A comparison of the fluorescence of telmisartan in pluronics with the well understood fluorescence of 8-anilino-1-naphthalene-sulfonic acid, a known fluorescent molecular probe, indicates that telmisartan is generally present in a relatively polar microenvironment with restricted diffusive motion.

  5. Coupling hydrogen separation with butanone hydrogenation in an electrochemical hydrogen pump with sulfonated poly (phthalazinone ether sulfone ketone) membrane

    NASA Astrophysics Data System (ADS)

    Huang, Shiqi; Wang, Tao; Wu, Xuemei; Xiao, Wu; Yu, Miao; Chen, Wei; Zhang, Fengxiang; He, Gaohong

    2016-09-01

    This work reports the novel work of coupling H2/CO2 separation with biomass-derived butanone hydrogenation in non-fluorinated sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK) electrochemical hydrogen pump (EHP) reactor. Due to higher resistance to swelling, SPPESK-based EHP reactor exhibits more excellent reaction rate in elevated temperature (60 °C) and higher butanone concentration (2 M) as 270, 260 nmol cm-2 s-1, respectively, higher than 240, 200 nmol cm-2 s-1of Nafion-based EHP reactors. Also, the SPPESK-based EHP reactor remains 90% of initial hydrogenation rate after 4 batches, better than that of Nafion-based EHP reactors, which is only 62%. The energy efficiency of EHP separator reaches 40% under H2/CO2 mixture feed mode, and electricity of about 0.3 kWh is consumed per Nm3 H2 product, being superior to energy consumption compared with alternative processes like PSA and electrolysis of water. In addition, SPPESK-based EHP exhibits better hydrogenation stability due to lower CO2 permeation than Nafion. With increasing CO2 content in H2 feed, hydrogenation rate almost keeps constant at around 210 nmol cm-2 s-1 in SPPESK-based EHP reactor while decreases fast to 50 nmol cm-2 s-1 in Nafion/PTFE-based EHP reactor. These results show integration of gas separation with hydrogenation reactor is feasible in SPPESK-based EHP reactor.

  6. An analysis of the kinetics of oxidation of ascorbate at poly(aniline)-poly(styrene sulfonate) modified microelectrodes.

    PubMed

    Bonastre, A M; Sosna, M; Bartlett, P N

    2011-03-28

    A detailed kinetic study is provided for the oxidation of ascorbate at poly(aniline)-poly(styrene sulfonate) coated microelectrodes. Flat films with a low degree of polymer spillover and a thickness much lower than the microelectrode radius were produced by controlled potentiodynamic electrodeposition. The currents for ascorbate oxidation are found to be independent of the polymer thickness, indicating that the reaction occurs at the outer surface of the polymer film. At low ascorbate concentrations, below around 40 mM, the currents are found to be mass transport limited. At higher ascorbate concentrations the currents became kinetically limited. The experimental data for measurements at a range of potentials are fitted to a consistent kinetic model and the results summarized in a case diagram. The results obtained for the poly(aniline)-(polystyrene sulfonate) coated microelectrode are compared to those for a poly(aniline)-poly(vinyl sulfonate) coated microelectrode and to the results of an earlier study of the reaction at poly(aniline)-poly(vinyl sulfonate) coated rotating disc electrodes. For poly(aniline)-poly(styrene sulfonate) the oxidation of ascorbate is found to proceed by one electron reaction whereas for poly(aniline)-poly(vinyl sulfonate) the reaction is found to be a two electron oxidation.

  7. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  8. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  9. Mapping protein cysteine sulfonic acid modifications with specific enrichment and mass spectrometry: an integrated approach to explore the cysteine oxidation.

    PubMed

    Chang, Yuan-Chang; Huang, Chien-Ning; Lin, Chia-Hung; Chang, Huan-Cheng; Wu, Chih-Che

    2010-08-01

    Oxidation of thiol proteins, which results in conversion of cysteine residues to cysteine sulfenic, sulfinic or sulfonic acids, is an important posttranslational control of protein function in cells. To facilitate the analysis of this process with MALDI-MS, we have developed a method for selective enrichment and identification of peptides containing cysteine sulfonic acid (sulfopeptides) in tryptic digests of proteins based on ionic affinity capture using polyarginine-coated nanodiamonds as high-affinity probes. The method was applied to selectively concentrate sulfopeptides from either a highly dilute solution or a complex peptide mixture in which the abundance of the sulfonated analyte is as low as 0.02%. The polyarginine-coated probes exhibit a higher affinity for peptides containing multiple sulfonic acids than peptides containing single sulfonic acid. The limit of the detection is in the femtomole range, with the MALDI-TOF mass spectrometer operating in the negative ion mode. The results show that the new approach has good specificity even in the presence of phosphopeptides. An application of this method for selective enrichment and structural identification of sulfopeptides is demonstrated with the tryptic digests of performic-acid-oxidized BSA.

  10. Aldicarb sulfone

    Integrated Risk Information System (IRIS)

    Aldicarb sulfone ; CASRN 1646 - 88 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  11. Preparation of a sulfonated carbonaceous material from lignosulfonate and its usefulness as an esterification catalyst.

    PubMed

    Lee, Duckhee

    2013-07-10

    Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%-29% after it was exposed to hot water (95 °C) for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

  12. Fate of perfluorinated carboxylates and sulfonates during snowmelt within an urban watershed.

    PubMed

    Meyer, Torsten; De Silva, Amila O; Spencer, Christine; Wania, Frank

    2011-10-01

    The transport dynamics of perfluorinated carboxylic acids and sulfonates during snowmelt in the highly urbanized Highland Creek watershed in Toronto, Canada was investigated by analyzing river water, bulk snow, and groundwater, sampled in February and March 2010, by means of liquid chromatography-tandem mass spectrometry. Perfluorohexanoate, perfluorooctanoate, and perfluorooctane sulfonate were dominant in river water, with concentrations of 4.0-14 ng·L(-1), 2.2-7.9 ng·L(-1), and 2.1-6.5 ng·L(-1), respectively. Relatively high levels of perfluorohexanoate may be related to the recent partial replacement in various consumer products of perfluorooctyl substances with shorter-chained perfluorinated compounds (PFCs). Highest PFC concentrations were found within the more urbanized part of the drainage area, suggestive of residential, industrial, and/or traffic-related sources. The riverine flux of PFCs increased during the snowmelt period, but only approximately one-fifth of the increased flux can be attributed to PFCs present in the snowpack, mostly because concentration in snow are generally quite low compared to those in river water. The remainder of the increased flux must be due to the mobilization of PFCs by the high flow conditions prevalent during snowmelt. Run-off behavior was clearly dependent on perfluoroalkyl chain length: Dilution with relatively clean snowmelt water caused a drop in the river water concentrations of short-chain PFCs at high flow during early melting. This prevented an early concentration peak of those water-soluble PFCs within the stream, as could have been expected in response to their early release from a melting snowpack. Instead, concentrations of particle-associated long-chain PFCs in creek water peaked early in the melt, presumably because high flow mobilized contaminated particles from impervious surfaces in the more urbanized areas of the watershed. The ability to enter the subsurface and deeper groundwater aquifers increased

  13. Fast responses of bacterial membranes to virus adsorption: a fluorescence study.

    PubMed Central

    Bayer, M E; Bayer, M H

    1981-01-01

    After collision with their host cells, virus particles may remain mobile on cell surfaces until they become attached at firm binding sites. We propose that a virion will arrive within a typical median time at such a site, generating a membrane signal such as an increased membrane fluorescence in cells labeled with the voltage-sensitive dyes 8-anilino-1-naphthalene-sulfonate (Mg-salt) (ANS), N-phenylnaphthylamine (NPA), or 3,3'-dipentyl-2,2'-oxacarbocyanine (di-O-C5[3]). We found that the time span between virus adsorption and fluorescence response varies widely among phages and also depends on bacterial strain, metabolic state, and type of dye. di-O-C5[3]-labeled cells react within 1 sec to uncouplers such as carbonyl cyanide m-chlorophenylhydrazone (CCCP). Cells labeled with ANS and NPA react to CCCP in 4-6 sec. Bacteriophages T4, T5, chi, and BF23, added to ANS-labeled cells, change the fluorescence in 9-15 sec. T-even ghosts cause a response at identical times. Baseplate-defective phage mutant T412- and isolated adsorption organelles of smaller viruses fail to cause an effect. di-O-C5[3]-labeled cells respond to T4 at a multiplicity of infection greater than or equal to 40 within 1 sec. A longer time (8 sec) is required at lower multiplicities. The receptor-degrading phages epsilon 15, epsilon 34, c 341, and K29 need the longest time (1 min for ANS) to cause a fluorescence increase. We suggest that the delayed fluorescence response is concomitant with the surface "walk" of the virion, which is terminated at an injection site. T4 tail sheath contraction coincides with the onset of the membrane fluorescence response. PMID:7029540

  14. Reshaping the folding energy landscape by chloride salt: impact on molten-globule formation and aggregation behavior of carbonic anhydrase.

    PubMed

    Borén, Kristina; Grankvist, Hannah; Hammarström, Per; Carlsson, Uno

    2004-05-21

    During chemical denaturation different intermediate states are populated or suppressed due to the nature of the denaturant used. Chemical denaturation by guanidine-HCl (GuHCl) of human carbonic anhydrase II (HCA II) leads to a three-state unfolding process (Cm,NI=1.0 and Cm,IU=1.9 M GuHCl) with formation of an equilibrium molten-globule intermediate that is stable at moderate concentrations of the denaturant (1-2 M) with a maximum at 1.5 M GuHCl. On the contrary, urea denaturation gives rise to an apparent two-state unfolding transition (Cm=4.4 M urea). However, 8-anilino-1-naphthalene sulfonate (ANS) binding and decreased refolding capacity revealed the presence of the molten globule in the middle of the unfolding transition zone, although to a lesser extent than in GuHCl. Cross-linking studies showed the formation of moderate oligomer sized (300 kDa) and large soluble aggregates (>1000 kDa). Inclusion of 1.5 M NaCl to the urea denaturant to mimic the ionic character of GuHCl leads to a three-state unfolding behavior (Cm,NI=3.0 and Cm,IU=6.4 M urea) with a significantly stabilized molten-globule intermediate by the chloride salt. Comparisons between NaCl and LiCl of the impact on the stability of the various states of HCA II in urea showed that the effects followed what could be expected from the Hofmeister series, where Li+ is a chaotropic ion leading to decreased stability of the native state. Salt addition to the completely urea unfolded HCA II also led to an aggregation prone unfolded state, that has not been observed before for carbonic anhydrase. Refolding from this state only provided low recoveries of native enzyme.

  15. Structural characterization and solution properties of a galacturonate polysaccharide derived from Aloe vera capable of in situ gelation.

    PubMed

    McConaughy, Shawn D; Stroud, Paul A; Boudreaux, Brent; Hester, Roger D; McCormick, Charles L

    2008-02-01

    A series of highly purified galacturonate polysaccharides have been extracted from the Aloe vera plant and analyzed in terms of chemical composition and molecular weight. This Aloe vera polysaccharide (AvP) has been found to exist as a high molecular weight species and possess a unique chemical composition, including a high galacturonic acid (GalA) content and low degree of methyl ester substitution. These factors facilitate gel formation upon exposure to low concentrations of calcium ions, leading to potential application in formulations designed for in situ nasal or subcutaneous protein delivery. Thorough examination of classic dilute solution properties, the [eta]-M(w), and R(g)-M(w) relationships, persistence length (L(p)), and inherent chain stiffness (B parameter), indicate an expanded random coil in aqueous salt solutions. The critical concentration for transition from dilute to concentrated solution, C(e), was determined by measuring both the zero shear viscosity (eta(o)) and fluorescence emission of the probe molecule 1,8-anilino-1-naphthalene sulfonic acid (1,8-ANS) as a function of polymer concentration. Examination of zeta potential and C(e) as a function of ionic strength indicates that the shift in C(e) from 0.60 to 0.30 wt % is related to an increased occurrence of intermolecular interactions at high salt concentrations. Additionally, dynamic rheology data are presented highlighting the ability of AvP to form gels at low polymer and calcium ion concentrations, exemplifying the technological potential of this polysaccharide for in situ drug delivery.

  16. Insights on Structural Characteristics and Ligand Binding Mechanisms of CDK2

    PubMed Central

    Li, Yan; Zhang, Jingxiao; Gao, Weimin; Zhang, Lilei; Pan, Yanqiu; Zhang, Shuwei; Wang, Yonghua

    2015-01-01

    Cyclin-dependent kinase 2 (CDK2) is a crucial regulator of the eukaryotic cell cycle. However it is well established that monomeric CDK2 lacks regulatory activity, which needs to be aroused by its positive regulators, cyclins E and A, or be phosphorylated on the catalytic segment. Interestingly, these activation steps bring some dynamic changes on the 3D-structure of the kinase, especially the activation segment. Until now, in the monomeric CDK2 structure, three binding sites have been reported, including the adenosine triphosphate (ATP) binding site (Site I) and two non-competitive binding sites (Site II and III). In addition, when the kinase is subjected to the cyclin binding process, the resulting structural changes give rise to a variation of the ATP binding site, thus generating an allosteric binding site (Site IV). All the four sites are demonstrated as being targeted by corresponding inhibitors, as is illustrated by the allosteric binding one which is targeted by inhibitor ANS (fluorophore 8-anilino-1-naphthalene sulfonate). In the present work, the binding mechanisms and their fluctuations during the activation process attract our attention. Therefore, we carry out corresponding studies on the structural characterization of CDK2, which are expected to facilitate the understanding of the molecular mechanisms of kinase proteins. Besides, the binding mechanisms of CDK2 with its relevant inhibitors, as well as the changes of binding mechanisms following conformational variations of CDK2, are summarized and compared. The summary of the conformational characteristics and ligand binding mechanisms of CDK2 in the present work will improve our understanding of the molecular mechanisms regulating the bioactivities of CDK2. PMID:25918937

  17. Likelihood-based molecular-replacement solution for a highly pathological crystal with tetartohedral twinning and sevenfold translational noncrystallographic symmetry

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; McCoy, Airlie J.; Read, Randy J.

    2014-02-01

    With the implementation of a molecular-replacement likelihood target that accounts for translational noncrystallographic symmetry, it became possible to solve the crystal structure of a protein with seven tetrameric assemblies arrayed translationally along the c axis. The new algorithm found 56 protein molecules in reduced symmetry (P1), which was used to resolve space-group ambiguity caused by severe twinning. Translational noncrystallographic symmetry (tNCS) is a pathology of protein crystals in which multiple copies of a molecule or assembly are found in similar orientations. Structure solution is problematic because this breaks the assumptions used in current likelihood-based methods. To cope with such cases, new likelihood approaches have been developed and implemented in Phaser to account for the statistical effects of tNCS in molecular replacement. Using these new approaches, it was possible to solve the crystal structure of a protein exhibiting an extreme form of this pathology with seven tetrameric assemblies arrayed along the c axis. To resolve space-group ambiguities caused by tetartohedral twinning, the structure was initially solved by placing 56 copies of the monomer in space group P1 and using the symmetry of the solution to define the true space group, C2. The resulting structure of Hyp-1, a pathogenesis-related class 10 (PR-10) protein from the medicinal herb St John’s wort, reveals the binding modes of the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS), providing insight into the function of the protein in binding or storing hydrophobic ligands.

  18. Insulin and heparin co-immobilized 3D polyester fabrics for the cultivation of fibroblasts in low-serum media.

    PubMed

    Türkoğlu Saşmazel, Hilal; Aday, Sezin; Gümüşderelioğlu, Menemşe

    2007-08-01

    Insulin and/or heparin immobilized/co-immobilized non-woven polyester fabric (NWPF) discs were developed for the cultivation of L929 mouse fibroblasts in low-serum media. At first, NWPF discs were hydrolyzed to obtain a carboxylic acid group-introduced matrix (NWPF-hydrolyzed). Insulin and heparin co-immobilized NWPF (NWPF-insulin-heparin) was prepared by the grafting of PEO onto NWPF-hydrolyzed disc (NWPF-PEO), followed by the reaction first with insulin and then heparin. In the presence of spacer arm, PEO, the amount of immobilized insulin molecules significantly increased from 6.96 to 84.45 microg/cm(2). The amount of heparin bound to the NWPF-PEO (5.93 microg/cm(2)) was higher than that of the insulin immobilized surface (4.59 microg/cm(2)). Insulin and heparin immobilized NWPF discs were observed with fluorescence microscopy by labeling the insulin and heparin with 8-anilino-1-naphthalene sulfonic acid (ANS) or fluorescein isothiocyanate (FITC), respectively. L929 fibroblasts were used to check the cell adhesion and cell growth capabilities of modified NWPF discs in low-serum media (containing 5% fetal bovine serum). Optical photographs showed that after 2nd day of the culture, fibroblastic cells spread along the length of modified fibers, eventually filling the interfiber space. At the end of 6-day growth period, cell yield in the presence of immobilized heparin was a little bit higher than that of the immobilized insulin. Co-immobilized (insulin/heparin) NWPF discs did not accelerate the cell growth as well as insulin or heparin immobilized discs. PMID:17576003

  19. Constructing proton-conductive highways within an ionomer membrane by embedding sulfonated polymer brush modified graphene oxide

    NASA Astrophysics Data System (ADS)

    Zhao, Liping; Li, Yifan; Zhang, Haoqin; Wu, Wenjia; Liu, Jindun; Wang, Jingtao

    2015-07-01

    Sulfonated polymer brush modified graphene oxide (SP-GO) fillers with controllable brush length are synthesized via the facile distillation-precipitation polymerization, and then incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate composite membranes. The influences of SP-GO upon the microstructures, including thermal and mechanical properties, water uptake/swelling, proton conduction, H2 permeability and single PEMFC performances of composite membranes are intensively investigated. It is found that the SP-GO fillers are uniformly dispersed and tend to lie perpendicularly to the cross-section surface of the whole membrane, which allow SP-GO fillers creating inter-connected and broad ionic pathways through the sulfonic acid groups in polymer brushes. Meanwhile, the SP-GO fillers connect the ionic clusters in SPEEK matrix via interfacial interactions. In such a way, proton-transfer highways are constructed along the SPEEK/SP-GO interface, which lower the proton transfer activation energy and enhance the proton conductivities of the composite membranes under both hydrated and anhydrous conditions. Furthermore, elevating the brush length on SP-GO could further enhance the proton conductivity. Compared to SPEEK control membrane, a 95.5% increase in hydrated conductivity, an 178% increase in anhydrous conductivity and a 37% increase in maximum power density are obtained for the optimal composite membrane.

  20. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat

    PubMed Central

    Dhaliwal, Amandeep K.; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S.

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar ‘Indian’. Released in early 1900s, ‘Indian’ is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, ‘gritty’ coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  1. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat.

    PubMed

    Dhaliwal, Amandeep K; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar 'Indian'. Released in early 1900s, 'Indian' is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, 'gritty' coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  2. Colorful Polyelectrolytes: An Atom Transfer Radical Polymerization Route to Fluorescent Polystyrene Sulfonate.

    PubMed

    Huberty, Wayne; Tong, Xiaowei; Balamurugan, Sreelatha; Deville, Kyle; Russo, Paul S; Zhang, Donghui

    2016-03-01

    A labeled green fluorescent polystyrene sulfonate (LNaPSS) has been synthesized using atom transfer radical polymerization of a styrene sulfonate monomer with a fluorescent co-monomer, fluorescein thiocyanate-vinyl aniline. As a result this 100 % sulfonated polymer contains no hydrophobic patches along the chain backbone besides the fluorescent marker itself. The concentration of the fluorescent monomer was kept low to maintain the characteristic properties of the anionic polyelectrolyte, LNaPSS. ATRP conditions facilitated the production of polymers spanning a range of molecular weights from 35,000 to 175,000 in gram-scale batches with polydispersity indices of 1.01-1.24. Molecular weight increased with the monomer to initiator ratio. Gel permeation chromatography results show a unimodal distribution, and the polymer structure was also confirmed by (1)H NMR and FT-IR spectroscopy. Fluorescence spectroscopy confirmed covalent bonding of fluorescein isothiocyanate to the polymer, indicating that the polymer is suitable as a probe in fluorescence microscopy. To demonstrate this ability, the polymer was used to locate structural features in salt crystals formed during drying, as in the evaporation of sea mist. A second application to probe diffusion studies is also demonstrated. PMID:26745991

  3. Oxidation of aromatic lithium thiolates into sulfinate salts: an attractive entry to aryl sulfones labeled with carbon-11.

    PubMed

    Martin, Claudie; Sandrinelli, Franck; Perrio, Cécile; Perrio, Stéphane; Lasne, Marie-Claire

    2006-01-01

    [reaction: see text] Aromatic 11C-sulfones were synthesized by S alkylation of lithium arenesulfinates, which are readily available from the corresponding thiols by an oxaziridine-mediated oxidation reaction with [11C]alkyl iodides in THF/H2O (4:1) at 150 degrees C. The radiosyntheses, including purification by HPLC, were completed in an average of 35 min from the end of the bombardment with 55-76% overall radiochemical yields (decay corrected). The described procedure extends the range of accessible labeling methods.

  4. Microbial characterization and degradation of linear alkylbenzene sulfonate in an anaerobic reactor treating wastewater containing soap powder.

    PubMed

    Carosia, Mariana Fronja; Okada, Dagoberto Yukio; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2014-09-01

    The aim of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) in an anaerobic fluidized bed reactor (AFBR) treating wastewater containing soap powder as LAS source. At Stage I, the AFBR was fed with a synthetic substrate containing yeast extract and ethanol as carbon sources, and without LAS; at Stage II, soap powder was added to this synthetic substrate obtaining an LAS concentration of 14 ± 3 mg L(-1). The compounds of soap powder probably inhibited some groups of microorganisms, increasing the concentration of volatile fatty acids (VFA) from 91 to 143 mg HAc L(-1). Consequently, the LAS removal rate was 48 ± 10% after the 156 days of operation. By sequencing, 16S rRNA clones belonging to the phyla Proteobacteria and Synergistetes were identified in the samples taken at the end of the experiment, with a remarkable presence of Dechloromonas sp. and Geobacter sp.

  5. Microbial characterization and degradation of linear alkylbenzene sulfonate in an anaerobic reactor treating wastewater containing soap powder.

    PubMed

    Carosia, Mariana Fronja; Okada, Dagoberto Yukio; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2014-09-01

    The aim of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) in an anaerobic fluidized bed reactor (AFBR) treating wastewater containing soap powder as LAS source. At Stage I, the AFBR was fed with a synthetic substrate containing yeast extract and ethanol as carbon sources, and without LAS; at Stage II, soap powder was added to this synthetic substrate obtaining an LAS concentration of 14 ± 3 mg L(-1). The compounds of soap powder probably inhibited some groups of microorganisms, increasing the concentration of volatile fatty acids (VFA) from 91 to 143 mg HAc L(-1). Consequently, the LAS removal rate was 48 ± 10% after the 156 days of operation. By sequencing, 16S rRNA clones belonging to the phyla Proteobacteria and Synergistetes were identified in the samples taken at the end of the experiment, with a remarkable presence of Dechloromonas sp. and Geobacter sp. PMID:24997374

  6. Examination of an aloe vera galacturonate polysaccharide capable of in situ gelation for the controlled release of protein therapeutics

    NASA Astrophysics Data System (ADS)

    McConaughy, Shawn David

    fluorescence emission of the probe molecule 1,8-anilino-1-naphthalene sulphonic acid (1,8-ANS) as a function of polymer concentration. Correlations are drawn between viscosity experiments and measurement of zeta potential. Increased degrees of intermolecular interactions are responsible for a shift of Ce to lower polymer concentrations with increasing ionic strength. Additionally, dynamic rheology data are presented highlighting the ability of AvP to form gels at low polymer and calcium ion concentrations, exemplifying the technological potential of this polysaccharide for in-situ drug delivery. In the second section, properties of Aloe vera galacturonate hydrogels formed via Ca2+ crosslinking have been studied in regard to key parameters influencing gel formation including molecular weight, ionic strength and molar ratio of Ca2+ to COO- functionality. Dynamic oscillatory rheology and pulsed field gradient NMR (PFG-NMR) studies have been conducted on hydrogels formed at specified Ca2+ concentrations in the presence and absence of Na+ and K+ ions, in order to assess the feasibility of in situ gelation for controlled delivery of therapeutics. Aqueous Ca2+ concentrations similar to those present in nasal and subcutaneous fluids induce the formation of elastic Aloe vera polysaccharide (AvP) hydrogel networks. By altering the ratio of Ca2+ to COO- functionality, networks may be tailored to provide elastic modulus (G') values between 20 and 20,000 Pa. The Aloe vera polysaccharide exhibits time dependent phase separation in the presence of monovalent electrolytes. Thus the relative rates of calcium induced gelation and phase separation become major considerations when designing a system for in situ delivery applications where both monovalent (Na+, K+) and divalent (Ca2+) ions are present. PFG-NMR and fluorescence microscopy confirm that distinctly different morphologies are present in gels formed in the presence and absence 0.15 M NaCl. Curve fitting of theoretical models to

  7. An eosin Y-based "turn-on" fluorescent sensor for detection of perfluorooctane sulfonate.

    PubMed

    Liang, Jiaman; Deng, Xiaoyan; Tan, Kejun

    2015-01-01

    In this paper, a novel sensing method with a higher sensitivity of perfluorooctane sulfonate (PFOS) than perfluorooctanoic acid (PFOA) has been proposed detection of PFOS in aqueous solution replying on the "off-on" switch of eosin Y/polyethyleneimine (PEI)/PFOS fluorescence system due to the higher affinity of PEI to PFOS than eosin Y. In pH 7.0 Britton-Robinson buffer solution, eosin Y reacts with protonated PEI to form complex by electrostatic attraction, which leads to a strong fluorescence quenching of the eosin Y. When PFOS presents, the fluorescence of eosin Y is recover due to the electrostatic and hydrophobic interactions between PFOS and PEI. The recovered fluorescence intensity is proportional to the concentration of PFOS in the ranging from 0 to 2.0×10(-6) mol/L with the limit of detection (LOD, 3σ) being 1.5×10(-8) mol/L without preconcentration. In this study, the optimum reaction conditions and the interferences of foreign substances were investigated. In addition, the effects of PFOA, the analog of PFOS, on the fluorescence recovery of the system were also studied. The presented approach has been successfully used to detect PFOS in real samples with RSD ⩽2.9%.

  8. Sulfonated poly(arylene ether sulfone)s with phosphine oxide moieties: a promising material for proton exchange membranes.

    PubMed

    Fu, Lingchao; Xiao, Guyu; Yan, Deyue

    2010-06-01

    Sulfonated poly(arylene ether sulfone)s with phosphine oxide moieties (sPESPO) were achieved by polycondensation of bis(4-hydroxyphenyl)phenylphosphine oxide with 3,3'-disulfonate-4,4'-difluorodiphenyl sulfone (SFDPS) and 4-fluorophenyl sulfone (FPSF). Sulfonated poly(arylene ether sulfone)s (sPES) were also synthesized by polymerization of 4,4'-sulfonyldiphenol with SFDPS and FPSF for comparison. The comparative study demonstrates that the sPESPO ionomers exhibit strong intermolecular interactions and high oxidative stability because of the phosphine oxide groups. Furthermore, the sPESPO membrane and the sPES membrane with an equal ion exchange capacity show much different nanophase separation morphology. As a result, the former shows better properties than the latter. The sPESPO membranes exhibit excellent overall properties. For instance, the sPESPO membrane, with a disulfonation degree of 45%, exhibits high thermal and oxidative stability. Moreover, it shows a water uptake of 30.8% and a swelling ratio of 15.8% as well as a proton conductivity of 0.087 S/cm at 80 degrees C.

  9. An Assessment of the Exposure of Americans to Perflourooctane Sulfonate: A Comparison of Estimated Intake with Values Inferred from NHANES Data

    EPA Science Inventory

    To better understand human exposure to perfluorinated compounds (PFCs), a model that assesses exposure to perfluorooctane sulfonate (PFOS) and its precursors from both an intake and a body burden perspective and combines the two with a simple pharmacokinetic (PK) model is demonst...

  10. Toxicity of an anionic detergent, dodecylbenzene sodium sulfonate, to a freshwater fish, Rita rita: determination of LC50 values by different methods.

    PubMed

    Roy, D

    1988-04-01

    LC50 values and their 95% confidence limits for various intervals of exposure to an anionic detergent, dodecylbenzene sodium sulfonate, have been determined using recommended methods. The advantages and disadvantages of these methods are discussed in light of the variations in the values. Different visible behaviors of the fish under the influence of the detergent have also been explained.

  11. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. Link to an amendment published at 79 FR 34636, June... substance identified generically as alkylbenzene sulfonate, amine salt (PMN P-90-456) is subject...

  12. Colon Necrosis Due to Sodium Polystyrene Sulfonate with and without Sorbitol: An Experimental Study in Rats

    PubMed Central

    Ayoub, Isabelle; Oh, Man S.; Gupta, Raavi; McFarlane, Michael; Babinska, Anna; Salifu, Moro O.

    2015-01-01

    Introduction Based on a single rat study by Lillemoe et al, the consensus has been formed to implicate sorbitol rather than sodium polystyrene sulfonate (SPS) as the culprit for colon necrosis in humans treated with SPS and sorbitol. We tested the hypothesis that colon necrosis by sorbitol in the experiment was due to the high osmolality and volume of sorbitol rather than its chemical nature. Methods 26 rats underwent 5/6 nephrectomy. They were divided into 6 groups and given enema solutions under anesthesia (normal saline, 33% sorbitol, 33% mannitol, SPS in 33% sorbitol, SPS in normal saline, and SPS in distilled water). They were sacrificed after 48 hours of enema administration or earlier if they were very sick. The gross appearance of the colon was visually inspected, and then sliced colon tissues were examined under light microscopy. Results 1 rat from the sorbitol and 1 from the mannitol group had foci of ischemic colonic changes. The rats receiving SPS enema, in sorbitol, normal saline, distilled water, had crystal deposition with colonic necrosis and mucosal erosion. All the rats not given SPS survived until sacrificed at 48 h whereas 11 of 13 rats that received SPS in sorbitol, normal saline or distilled water died or were clearly dying and sacrificed sooner. There was no difference between sorbitol and mannitol when given without SPS. Conclusions In a surgical uremic rat model, SPS enema given alone or with sorbitol or mannitol seemed to cause colon necrosis and high mortality rate, whereas 33% sorbitol without SPS did not. PMID:26413782

  13. Denaturant effects on HbGp hemoglobin as monitored by 8-anilino-1-naphtalene-sulfonic acid (ANS) probe.

    PubMed

    Barros, Ana E B; Carvalho, Francisco A O; Alves, Fernanda R; Carvalho, José W P; Tabak, Marcel

    2015-03-01

    Glossoscolex paulistus extracellular hemoglobin (HbGp) stability has been monitored in the presence of denaturant agents. 8-Anilino-1-naphtalene-sulfonic acid (ANS) was used, and spectroscopic and hydrodynamic studies were developed. Dodecyltrimethylammonium bromide (DTAB) induces an increase in ANS fluorescence emission intensity, with maximum emission wavelength blue-shifted from 517 to 493 nm. Two transitions are noticed, at 2.50 and 9.50 mmol/L of DTAB, assigned to ANS interaction with pre-micellar aggregates and micelles, respectively. In oxy-HbGp, ANS binds to protein sites less exposed to solvent, as compared to DTAB micelles. In DTAB-HbGp-ANS ternary system, at pH 7.0, protein aggregation, oligomeric dissociation and unfolding were observed, while, at pH 5.0, aggregation is absent. DTAB induced unfolding process displays two transitions, one due to oligomeric dissociation and the second one, probably, to the denaturation of dissociated subunits. Moreover, guanidine hydrochloride and urea concentrations above 1.5 and 4.0 mol/L, respectively, induce the full HbGp denaturation, with reduction of ANS-bound oxy-HbGp hydrophobic patches, as noticed by fluorescence quenching up to 1.0 and 5.0 mol/L of denaturants. Our results show clearly the differences in probe sensitivity to the surfactant, in the presence and absence of protein, and new insights into the denaturant effects on HbGp unfolding.

  14. Morphology of a blend of zinc neutralized sulfonated poly(phenylene oxide) or polystyrene and an amino silicone

    SciTech Connect

    Jones, A.A.; Inglefield, P.T.; Zhang, Changlai; Bergquist, P

    1996-12-31

    A polymer blend of an ionomer based on zinc neutralized sulfonated poly(phenylene oxide) or polystyrene with a silicone copolymer containing 6.45% propylamine groups in place of one of the methyl groups on a backbone silicon was prepared. Carbon-13 magic angle spinning spectra show coordination of the amine, by the zinc ions. Morphological characterization was made by NMR spectroscopy based on proton spin diffusion, by small angle x-ray scattering and by energy filtered transmission electron microscopy. All experiments show domains in the range of 1 to 1000 nm and domain size can be controlled by the extent of coordination of the amine groups by the zinc ions and by thermal history. The different lead to an apparent hierarchy of domain sizes. The NMR domains, 2 to 10 nm, where contrast is produced by differences in chain mobility. Small angle x-ray scattering indicates domains of 16 nm while electron in the range of 100 to 1000 nm. The variation of the domain size between experiments may reflect the different sources of contrast in each cam.

  15. Reaction of Lithium Diethylamide with an Alkyl Bromide and Alkyl Benzenesulfonate: Origins of Alkylation, Elimination, and Sulfonation

    PubMed Central

    Gupta, Lekha; Ramírez, Antonio; Collum, David B.

    2010-01-01

    A combination of NMR, kinetic, and computational methods are used to examine reactions of lithium diethylamide in tetrahydrofuran (THF) with n-dodecyl bromide and n-octyl benzenesulfonate. The alkyl bromide undergoes competitive SN2 substitution and E2 elimination in proportions independent of all concentrations except for a minor medium effect. Rate studies show that both reactions occur via trisolvated-monomer-based transition structures. The alkyl benzenesulfonate undergoes competitive SN2 substitution (minor) and N-sulfonation (major) with N-sulfonation promoted at low THF concentrations. The SN2 substitution is shown to proceed via a disolvated monomer suggested computationally to involve a cyclic transition structure. The dominant N-sulfonation follows a disolvated-dimer-based transition structure suggested computationally to be a bicyclo[3.1.1] form. The differing THF and lithium diethylamide orders for the two reactions explain the observed concentration-dependent chemoselectivities. PMID:21077695

  16. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    PubMed

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion.

  17. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    PubMed

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion. PMID:26448524

  18. Aromatic sulfide/sulfone polymer production

    SciTech Connect

    Scoggins, L.E.; Hoover, K.C.; Shang, W.W.

    1991-05-14

    This patent describes a process for the production of aromatic sulfide/sulfone polymer. It comprises: contacting at least one lactam, at least one alkali metal hydrosulfide, water, and at least one base selected from the group consisting of alkali metal hydroxides and mixtures of alkali metal hydroxides with alkali metal carbonates under reaction conditions of time and temperature sufficient to produce a mixture containing a complex which comprises the at least one alkali metal hydrosulfide and contacting the mixture produced with a least one dihaloaromatic sulfone under polymerization conditions for a period of time sufficient to form an aromatic sulfide/sulfone polymer.

  19. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    NASA Astrophysics Data System (ADS)

    Yasuoka, K.; Sasaki, K.; Hayashi, R.

    2011-06-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l-1 (54.8% of the initial amount of fluorine atoms) and 26 mg kWh-1, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  20. Self-organization of surfactant molecules on solid surface: an STM study of sodium alkyl sulfonates [rapid communication

    NASA Astrophysics Data System (ADS)

    Yin, Xiu-Li; Wan, Li-Jun; Yang, Zheng-Yu; Yu, Jia-Yong

    2005-02-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) on HOPG have been studied by using in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on HOPG surface and form long-range well-ordered monolayers. The molecular rows and the axes of alkyl chain of the molecules cross each other at angles of 60° and 90° in the STS and SHS layers, respectively. Molecular details such as sulfonate functional group (head) and alkyl chain are clearly imaged. The neighboring molecules in different rows form a "head to head" configuration. Structural models for the molecular arrangement of the two adlayers are proposed.

  1. Sulfonated polyphenylene polymers

    DOEpatents

    Cornelius, Christopher J.; Fujimoto, Cy H.; Hickner, Michael A.

    2007-11-27

    Improved sulfonated polyphenylene compositions, improved polymer electrolyte membranes and nanocomposites formed there from for use in fuel cells are described herein. The improved compositions, membranes and nanocomposites formed there from overcome limitations of Nafion.RTM. membranes.

  2. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... is used to treat hyperkalemia (increased amounts of potassium in the body). Sodium polystyrene sulfonate is in a class of medications called potassium-removing agents. It works by removing excess potassium ...

  3. Addition of sulfonated silicon dioxide on an anode catalyst layer to improve the performance of a self-humidifying proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Liang; Hsu, Shih-Chieh; Ho, Wei-Yu

    2016-03-01

    Sulfonated SiO2 was added on an anode catalyst layer to manufacture a hygroscopic electrode for self-humidifying proton exchange membrane fuel cells (PEMFCs). The inherent humidity of a proton exchange membrane (PEM) determines the electrical performance of PEMFCs. To maintain the high moisture content of the PEM, self-humidifying PEMFCs can use the water produced by the fuel cell reaction and, thus, do not require external humidification. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and water contact angle measurement tests were performed to characterize the structures and properties of sulfonated SiO2 and the related electrodes, and the electric current and voltage (I-V) performance curve tests for the fuel cells were conducted under differing gas humidification conditions. When 0.01mg/cm2 of sulfonated SiO2 was added, the electrical performance of the fuel cells (50∘C) increased 29% and 59% when the fuel cell reaction gases were humidified at 70∘C and 50∘C, respectively.

  4. Crystal structure of zwitterionic bisimidazolium sulfonates

    NASA Astrophysics Data System (ADS)

    Kohmoto, Shigeo; Okuyama, Shinpei; Yokota, Nobuyuki; Takahashi, Masahiro; Kishikawa, Keiki; Masu, Hyuma; Azumaya, Isao

    2012-05-01

    Crystal structures of three zwitterionic bisimidazolium salts 1-3 in which imidazolium sulfonate moieties were connected with aromatic linkers, p-xylylene, 4,4'-dimethylenebiphenyl, and phenylene, respectively, were examined. The latter two were obtained as hydrates. An S-shaped molecular structure in which the sulfonate moiety was placed on the imidazolium ring was observed for 1. A helical array of hydrated water molecules was obtained for 2 while a linear array of hydrated water molecules was observed for 3.

  5. Phytoremediation of sulfonated Remazol Red dye and textile effluents by Alternanthera philoxeroides: An anatomical, enzymatic and pilot scale study.

    PubMed

    Rane, Niraj R; Chandanshive, Vishal V; Watharkar, Anuprita D; Khandare, Rahul V; Patil, Tejas S; Pawar, Pankaj K; Govindwar, Sanjay P

    2015-10-15

    Alternanthera philoxeroides Griseb. a macrophyte was found to degrade a highly sulfonated textile dye Remazol Red (RR) completely within 72 h at a concentration of 70 mg L(-1). An induction in the activities of azoreductase and riboflavin reductase was observed in root and stem tissues; while the activities of lignin peroxidase, laccase and DCIP reductase were induced in leaf tissues. Some enzymes namely tyrosinase, veratryl alcohol oxidase, catalase and superoxide dismutase displayed an increase in their activity in all the tissues in response of 72 h exposure to Remazol Red. There was a marginal reduction in contents of chlorophyll a (20%), chlorophyll b (5%) and carotenoids (16%) in the leaves when compared to control plants. A detailed anatomical study of the stem during uptake and treatment revealed a stepwise mechanism of dye degradation. UV-vis spectrophotometric and high performance thin layer chromatographic analyses confirmed the removal of parent dye from solution. Based on the enzymes activities and gas chromatography-mass spectroscopic analysis of degradation products, a possible pathway of phytotransformation of RR was proposed which revealed the formation of 4-(phenylamino)-1,3,5-triazin-2-ol, naphthalene-1-ol and 3-(ethylsulfonyl)phenol. Toxicity study on Devario aequipinnatus fishes showed that the anatomy of gills of fishes exposed to A. philoxeroides treated RR was largely protected. The plants were further explored for rhizofiltration experiments in a pilot scale reactor. A. philoxeroides could decolorize textile industry effluent of varying pH within 96 h of treatment which was evident from the significant reductions in the values of American dye manufacturers' institute color, chemical oxygen demand, biological oxygen demand, total dissolved and total suspended solids.

  6. Phytoremediation of sulfonated Remazol Red dye and textile effluents by Alternanthera philoxeroides: An anatomical, enzymatic and pilot scale study.

    PubMed

    Rane, Niraj R; Chandanshive, Vishal V; Watharkar, Anuprita D; Khandare, Rahul V; Patil, Tejas S; Pawar, Pankaj K; Govindwar, Sanjay P

    2015-10-15

    Alternanthera philoxeroides Griseb. a macrophyte was found to degrade a highly sulfonated textile dye Remazol Red (RR) completely within 72 h at a concentration of 70 mg L(-1). An induction in the activities of azoreductase and riboflavin reductase was observed in root and stem tissues; while the activities of lignin peroxidase, laccase and DCIP reductase were induced in leaf tissues. Some enzymes namely tyrosinase, veratryl alcohol oxidase, catalase and superoxide dismutase displayed an increase in their activity in all the tissues in response of 72 h exposure to Remazol Red. There was a marginal reduction in contents of chlorophyll a (20%), chlorophyll b (5%) and carotenoids (16%) in the leaves when compared to control plants. A detailed anatomical study of the stem during uptake and treatment revealed a stepwise mechanism of dye degradation. UV-vis spectrophotometric and high performance thin layer chromatographic analyses confirmed the removal of parent dye from solution. Based on the enzymes activities and gas chromatography-mass spectroscopic analysis of degradation products, a possible pathway of phytotransformation of RR was proposed which revealed the formation of 4-(phenylamino)-1,3,5-triazin-2-ol, naphthalene-1-ol and 3-(ethylsulfonyl)phenol. Toxicity study on Devario aequipinnatus fishes showed that the anatomy of gills of fishes exposed to A. philoxeroides treated RR was largely protected. The plants were further explored for rhizofiltration experiments in a pilot scale reactor. A. philoxeroides could decolorize textile industry effluent of varying pH within 96 h of treatment which was evident from the significant reductions in the values of American dye manufacturers' institute color, chemical oxygen demand, biological oxygen demand, total dissolved and total suspended solids. PMID:26164661

  7. An experimental and theoretical method for determination of standard electrode potential for the redox couple diphenyl sulfone/diphenyl sulfide

    NASA Astrophysics Data System (ADS)

    Song, Y. Z.; Wei, K. X.; Lv, J. S.

    2013-12-01

    DFT calculations were performed for diphenyl sulfide and diphenyl sulfone. The electrochemistry of diphenyl sulfide on the gold electrode was investigated by cyclic voltammety and the results show that standard electrode potential for redox couple diphenyl sulfone/diphenyl sulfide is 1.058 V, which is consistent with that of 1.057 calculated at B3LYP/6-31++G( d, p)-IEFPCM level. The front orbit theory and Mulliken charges of molecular explain well on the oxidation of diphenyl sulfide in oxidative desulfurization. According to equilibrium theory the experimental equilibrium constant in the oxidative desulfurization of H2O2, is 1.17 × 1048, which is consistent with the theoretical equilibrium constant is 2.18 × 1048 at B3LYP/6-31++G( d, p)-IEFPCM level.

  8. Phase equilibria in a system of aqueous arginine with an octane solution of sulfonic acid

    NASA Astrophysics Data System (ADS)

    Kuvaeva, Z. I.; Koval'chuk, I. V.; Vodop'yanova, L. A.; Soldatov, V. S.

    2013-05-01

    The extraction of arginine (Arg) from aqueous salt (0.1 M NaCl) solutions with a sulfo extractant in a wide range of pH values and amino acid concentrations was studied. The 0.1 M solution of dinonylnaphthalenesulfonic acid (HD) in octane was used as an extractant. The degree of extraction was found to be high at pH 0.8-9.0. This can be explained by the effect of additional intermolecular interactions in the extractant phase involving the guanidine group of Arg.

  9. [Fluorescence used to investigate the sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation].

    PubMed

    Xi, Gang; Yang, Yun-Jing; Lu, Hong

    2009-07-01

    A system for studying biological effect of radio frequency electromagnetic field was developed. The system can form an area where electromagnetic wave with large frequency range is well distributed. The strength of electromagnetic wave was measured easily. Electromagnetic wave in the system did not have effect on environment. The sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation of 300 MHz under power density of 5 mW x cm(-2) was studied by the spectral analysis method of fluorescence of 8-anilino-1-naphthalene-sulfonic acid (ANS) and the changes in chlorophyll a (Chla) fluorescence parameters of spinach chloroplast membrane. The result showed that the position of spectrum of ANS fluorescence of spinach chloroplast membrane did not change, but the intensity of ANS fluorescence was obviously increased under the action of electromagnetic radiation with power density of 1-5 mW x cm(-2). There was an increase in the intensity of ANS fluorescence with the increase in electromagnetic radiation. The increase of ANS fluorescence of spinach chloroplast membrane showed that low level electromagnetic field induced the decrease in fluidity of chloroplast membrane compared with control experiment. The cause of the change in the fluidity could be related to the polarization of chloroplast membrane under the electromagnetic field. The analysis of Chla fluorescence parameters of spinach chloroplast membrane indicated that low level electromagnetic field of 300 MHz made the fluorescence parameters F0 and F(VI/)F(V) decrease, and F(V)/Fo, Fv/F(m) and deltaF(V)/T increase. It was showed that low level electromagnetic field caused the change of non-active center of photosystem II of spinach chloroplast membrane to active center and the increase in potential active and photochemical efficiency of PSII, and promoted the transmit process of electron in photosynthesis of chloroplast membrane of photosynthesis cell in spinach leaf. The study confirmed

  10. Lipid binding ability of human apolipoprotein E N-terminal domain isoforms: correlation with protein stability?

    PubMed

    Weers, Paul M M; Narayanaswami, Vasanthy; Choy, Nicole; Luty, Robert; Hicks, Les; Kay, Cyril M; Ryan, Robert O

    2003-01-01

    Human apolipoprotein (apo) E exists as one of three major isoforms, E2, E3 or E4. Individuals carrying the epsilon 4 allele have an increased risk of heart disease and premature onset of Alzheimer's disease. To investigate the molecular basis for this phenomenon, the N-terminal domain of apoE3, apoE2 and apoE4 were expressed in bacteria, isolated and employed in lipid binding and stability studies. Far UV circular dichroism spectroscopy in buffer at pH 7 revealed a similar amount of alpha-helix secondary structure for the three isoforms. By contrast, differences were noted in apoE-NT isoform-specific transformation of bilayer vesicles of dimyristoylphosphatidylglycerol (DMPG) into discoidal complexes. ApoE4-NT induced transformation was most rapid, followed by apoE3-NT and apoE2-NT. To determine if differences in the rate of apoE-NT induced DMPG vesicle transformation is due to isoform-specific differences in helix bundle stability, guanidine HCl denaturation studies were conducted. The results revealed that apoE2-NT was the most stable, followed by apoE3-NT and apoE4-NT, establishing an inverse correlation between helix bundle stability and DMPG vesicle transformation rate at pH 7. When the zwitterionic dimyristoylphosphatidylcholine (DMPC) was employed as the model lipid surface, interaction of apoE-NT isoforms with the lipid substrate was slow. However, upon lowering the pH from 7 to 3, a dramatic increase in the rate of DMPC vesicle transformation rate was observed for each isoform. To evaluate if the increased DMPC vesicle transformation rates observed at low pH is due to pH-dependent alterations in helix bundle stability, guanidine HCl denaturation studies were performed. ApoE2-NT and apoE3-NT displayed increased resistance to denaturation as a function of decreasing pH, while apoE4-NT showed no change in stability. Studies with the fluorescent probe, 8-anilino-1-naphthalene sulfonic acid, indicated an increase in apoE hydrophobic surface exposure upon

  11. Development of a Radioiodinated Triazolopyrimidine Probe for Nuclear Medical Imaging of Fatty Acid Binding Protein 4

    PubMed Central

    Onoe, Satoru; Sampei, Sotaro; Kimura, Ikuo; Ono, Masahiro; Saji, Hideo

    2014-01-01

    Fatty acid binding protein 4 (FABP4) is the most well-characterized FABP isoform. FABP4 regulates inflammatory pathways in adipocytes and macrophages and is involved in both inflammatory diseases and tumor formation. FABP4 expression was recently reported for glioblastoma, where it may participate in disease malignancy. While FABP4 is a potential molecular imaging target, with the exception of a tritium labeled probe there are no reports of other nuclear imaging probes that target this protein. Here we designed and synthesized a nuclear imaging probe, [123I]TAP1, and evaluated its potential as a FABP4 targeting probe in in vitro and in vivo assays. We focused on the unique structure of a triazolopyrimidine scaffold that lacks a carboxylic acid to design the TAP1 probe that can undergo facilitated delivery across cell membranes. The affinity of synthesized TAP1 was measured using FABP4 and 8-anilino-1-naphthalene sulfonic acid. [125I]TAP1 was synthesized by iododestannylation of a precursor, followed by affinity and selectivity measurements using immobilized FABPs. Biodistributions in normal and C6 glioblastoma-bearing mice were evaluated, and excised tumors were subjected to autoradiography and immunohistochemistry. TAP1 and [125I]TAP1 showed high affinity for FABP4 (Ki = 44.5±9.8 nM, Kd = 69.1±12.3 nM). The FABP4 binding affinity of [125I]TAP1 was 11.5- and 35.5-fold higher than for FABP3 and FABP5, respectively. In an in vivo study [125I]TAP1 displayed high stability against deiodination and degradation, and moderate radioactivity accumulation in C6 tumors (1.37±0.24% dose/g 3 hr after injection). The radioactivity distribution profile in tumors partially corresponded to the FABP4 positive area and was also affected by perfusion. The results indicate that [125I]TAP1 could detect FABP4 in vitro and partly in vivo. As such, [125I]TAP1 is a promising lead compound for further refinement for use in in vivo FABP4 imaging. PMID:24732569

  12. Syntheses and structures of a series of uranyl phosphonates and sulfonates: an insight into their correlations and discrepancies.

    PubMed

    Yang, Weiting; Tian, Tao; Wu, Hong-Yue; Pan, Qing-Jiang; Dang, Song; Sun, Zhong-Ming

    2013-03-01

    Six uranyl phosphonates and sulfonates have been hydrothermally synthesized, namely, (H2tib)[(UO2)3(PO3C6H5)4]·2H2O (UPhP-1), Zn(pi)2(UO2)(PO3C6H5)2 (UPhP-2), Zn(dib)(UO2)(PO3C6H5)2·2H2O (UPhP-3), (HTEA)[(UO2)(5-SP)] (USP-1), (Hdib)2[(UO2)2(OH)(O)(5-SP)] (USP-2), and Zn(phen)3(UO2)2(3-SP)2 (USP-3) (tib = 1,3,5-tri(1H-imidazol-1-yl)benzene, pi = 1-phenyl-1H-imidazole, dib = 1,4-di(1H-imidazol-1-yl)benzene, TEA = triethylamine, phen = 1,10-phenanthroline, 5-SP = 5-sulfoisophthalic acid, and 3-SP = 3-sulfoisophthalic acid). UPhP-1 has been determined to be a layered structure constructed by UO7 pentagonal bipyramids, UO6 octahedra, and phenylphosphonates. Protonated tib plays a role in balancing the negative charge and holding its structure together. UPhP-2 is made up of UO6 octahedra, ZnO2N2 tetrahedra and PO3C tetrahedra in phenylphosphonates, forming a 1D assembly, which is stabilized by chelate phen ligand. Further connection of such chainlike structure via dib yields a 2D layered architecture of UPhP-3. Although sulfonate group possesses similar tetrahedral structure as the phosphonate group, a unidentated coordination mode is only found in this work. UO7 pentagonal bipyramids are linked by 5-SP to form the layered assembly of USP-1. USP-2 also consists of the same sulfonate ligand, but features tetranulear uranyl clusters. Similarly, protonated TEA and dib molecules enable stabilization of their structures, respectively. Formed by dinuclear uranyl cluster and 3-SP ligand, USP-3 appears as a 1D arrangement, in which Zn(phen)3 acts as the counterion to compensate the negative charge. All of these compounds have been characterized by IR and photoluminescent spectroscopy. Their characteristic emissions have been attributed as transition properties of uranyl cations.

  13. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT.
    C. Lau and J.M. Rogers, Reproductive Toxicology Division, NHEERL, ORD, USEPA, Research Triangle Park, NC, USA

    Perfluorooctane sulfonate (PFOS), an environmentally persistent compound used ...

  14. Radiation grafted and sulfonated (FEP-g-polysterene) - An alternative to perfluorinated membranes for PEM fuel cells?

    NASA Astrophysics Data System (ADS)

    Buechi, F. N.; Gupta, B.; Rouilly, M.; Hauser, P. C.; Chapiro, A.; Scherer, G. G.

    Partially fluorinated proton exchange membranes (PEMs) were synthesized for fuel cell applications by simultaneous radiation grafting of styrene on FEP films followed by sulfonation. Properties of the synthesized membranes can be tailored by varying the degree of grafting and crosslinking. The performance of these membranes was tested in H2/O2 fuel cells. Long time testing showed steady performance for high grafted membranes over periods of more than 300 h at a cell temperature of 60 C. Low grafted membranes and the Morgane CDS membrane showed considerable decay of cell power on the same time scale. A fast degradation of all membranes occurred at a cell temperature of 80 C. It is noted that grafting in film form makes this process a potentially cheap and easy technique for the preparation of solid polymer fuel cell electrolytes.

  15. Sulfonic acid-functionalized silica-coated magnetic nanoparticles as an efficient reusable catalyst for the synthesis of 1-substituted 1H-tetrazoles under solvent-free conditions.

    PubMed

    Naeimi, Hossein; Mohamadabadi, Samaneh

    2014-09-14

    Regarding green chemistry goals, silica-coated magnetite nanoparticles open up a new avenue to introduce a very useful and efficient system for facilitating catalyst recovery in different organic reactions. Therefore, in this paper the preparation of sulfonic acid-functionalized silica-coated magnetic nanoparticles with core-shell structure (Fe3O4@silica sulfonic acid) is presented by using Fe3O4 spheres as the core and silica sulfonic acid nanoparticles as the shell. The catalyst was characterized by infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, dynamic light scattering, thermogravimetric analysis and vibrating sample magnetometry. Nanocatalyst can be recovered using an external magnet and reused for subsequent reactions 6 times without noticeable deterioration in catalytic activity.

  16. Vinyl sulfone silica: application of an open preactivated support to the study of transnitrosylation of plant proteins by S-nitrosoglutathione

    PubMed Central

    2013-01-01

    Background S-nitrosylaton is implicated in the regulation of numerous signaling pathways with a diversity of regulatory roles. The high lability of the S-NO bond makes the study of proteins regulated by S-nitrosylation/denitrosylation a challenging task and most studies have focused on already S-nitrosylated proteins. We hypothesize that: i) S-nitrosoglutathione (GSNO) transnitrosylation is a feasible mechanism to account for the physiological S-nitrosylation of rather electropositive sulfur atoms from proteins, ii) affinity chromatography is a suitable approach to isolate proteins that are prone to undergo S-transnitrosylation and iii) vinyl sulfone silica is a suitable chromatographic bead. Results The combination of vinyl sulfone silica with GSNO yielded an affinity resin that withstood high ionic strength without shrinking or deforming and that it was suitable to isolate potential GSNO transnitrosylation target candidates. Fractions eluted at 1500 mM NaCl resulted in a symmetrical peak for both, protein and S-nitrosothiols, supporting the idea of transnitrosylation by GSNO as a selective process that involves strong and specific interactions with the target protein. Proteomic analysis led to the identification of 22 physiological significant enzymes that differ with the tissue analyzed, being regulatory proteins the most abundant group in hypocotyls. The identification of chloroplastidic FBPase, proteasome, GTP-binding protein, heat shock Hsp70, syntaxin, catalase I, thioredoxin peroxidase and cytochrome P450 that have already been reported as S-nitrosylated by other techniques can be considered as internal positive controls that validate our experimental approach. An additional validation was provided by the prediction of the S-nitrosylation sites in 19 of the GSNO transnitrosylation target candidates. Conclusions Vinyl sulfone silica is an open immobilization support that can be turned ad hoc and in a straightforward manner into an affinity resin. Its

  17. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  18. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  19. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  20. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  1. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  2. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  3. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  4. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  5. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  6. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  7. Perfluorooctane sulfonate (PFOS) depletion in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is used as a surfactant in several manufactured consumer products but is also a breakdown product from other chemical surfactants. As a result of its extensive use, PFOS is ubiquitous in the environment and is often detected in biosoli...

  8. Correlating electronic structure and chemical durability of sulfonated poly(arylene ether sulfone)s

    NASA Astrophysics Data System (ADS)

    Lawrence, Jimmy; Yamashita, Koichi; Yamaguchi, Takeo

    2015-04-01

    Many different proton-conducting polymeric materials have been developed for polymer electrolyte membrane fuel cells (PEMFCs). The development of perfluorosulfonic acid-based, polymer electrolyte membranes (PFSA-PEMs) was followed by aromatic hydrocarbon-based PEMs (HC-PEMs), which allow for tailored design and optimization of their molecular structures. Although many new PFSA-PEMs and HC-PEMs have shown promising proton conductivity and thermal stability, chemical degradation of these materials in an oxidizing environment remains a significant technical barrier in PEMFC development. Here, we used accelerated degradation tests and electronic structure analysis to examine the chemical stability of sulfonated poly(arylene ether sulfone) (SPES) copolymers, a highly thermally stable HC-PEM. HOMO levels, the presence of main chain-protecting steric groups, and HOMO-LUMO location along the main chain have significant effects on the chain scission modes and degradation rate of SPES copolymers. Rational design of HC-PEMs to suppress midpoint scission can open many opportunities in the development of highly robust polymer electrolytes for fuel cell and other energy storage applications.

  9. Phase Behavior of Symmetric Sulfonated Block Copolymers

    SciTech Connect

    Park, Moon Jeong; Balsara, Nitash P.

    2008-08-21

    Phase behavior of poly(styrenesulfonate-methylbutylene) (PSS-PMB) block copolymers was studied by varying molecular weight, sulfonation level, and temperature. Molecular weights of the copolymers range from 2.9 to 117 kg/mol. Ordered lamellar, gyroid, hexagonally perforated lamellae, and hexagonally packed cylinder phases were observed in spite of the fact that the copolymers are nearly symmetric with PSS volume fractions between 0.45 and 0.50. The wide variety of morphologies seen in our copolymers is inconsistent with current theories on block copolymer phase behavior such as self-consistent field theory. Low molecular weight PSS-PMB copolymers (<6.2 kg/mol) show order-order and order-disorder phase transitions as a function of temperature. In contrast, the phase behavior of high molecular weight PSS-PMB copolymers (>7.7 kg/mol) is independent of temperature. Due to the large value of Flory-Huggins interaction parameter, x, between the sulfonated and non-sulfonated blocks, PSS-PMB copolymers with PSS and PMB molecular weights of 1.8 and 1.4 kg/mol, respectively, show the presence of an ordered gyroid phase with a 2.5 nm diameter PSS network. A variety of methods are used to estimate x between PSS and PMB chains as a function of sulfonation level. Some aspects of the observed phase behavior of PSS-PMB copolymers can be rationalized using x.

  10. Sulfonated Polymerized Ionic Liquid Block Copolymers.

    PubMed

    Meek, Kelly M; Elabd, Yossef A

    2016-07-01

    The successful synthesis of a new diblock copolymer, referred to as sulfonated polymerized ionic liquid (PIL) block copolymer, poly(SS-Li-b-AEBIm-TFSI), is reported, which contains both sulfonated blocks (sulfonated styrene: SS) and PIL blocks (1-[(2-acryloyloxy)ethyl]-3-butylimidazolium: AEBIm) with both mobile cations (lithium: Li(+) ) and mobile anions (bis(trifluoromethylsulfonyl)imide: TFSI(-) ). Synthesis consists of polymerization via reversible addition-fragmentation chain transfer, followed by post-functionalization reactions to covalently attach the imidazolium cations and sulfonic acid anions to their respective blocks, followed by ion exchange metathesis resulting in mobile Li(+) cations and mobile TFSI(-) anions. Solid-state films containing 1 m Li-TFSI salt dissolved in ionic liquid result in an ion conductivity of >1.5 mS cm(-1) at 70 °C, where small-angle X-ray scattering data indicate a weakly ordered microphase-separated morphology. These results demonstrate a new ion-conducting block copolymer containing both mobile cations and mobile anions. PMID:27125600

  11. Properties of polypyrrole doped with alkylbenzene sulfonates

    NASA Astrophysics Data System (ADS)

    Bay, Lasse; Skaarup, Steen; West, Keld; Mazur, Tanja; Joergensen, Ole; Rasmussen, Helle D.

    2001-07-01

    Conducting polymers such as polypyrrole (PPy) doped with large anionic detergents have high stability in aqueous systems. PPy can be reversibly oxidised and reduced electrochemically. The redox change of PPy is accompanied by a change in volume of the polymer. This is partly ascribed to take-up of ions and solvent molecules. This volume change can be used as a polymer actuator (artificial muscle) working in a narrow voltage range (less than 1 V). The properties of the PPy polymer are largely determined by the dopant ions and also by the deposition conditions and the substrate. A free-standing 10 micrometers thick film is prepared electrochemically at a constant current from an aqueous solution of pyrrole and sodium alkylbenzene sulfonate. The mechanical properties of the film (tensile strength and Young's modulus) and the reversible linear elongation between the oxidised and reduced states are measured. Alkylbenzene sulfonates with alkyl chain lengths between 1 and 22 carbon atoms are used as dopant anion. The films made with the different anions have highly different properties and are here compared to outline the influence of the size of the anion. A maximum in linear elongation is found for p-(n-octyl)benzene sulfonate and in conductivity for p-(n-butyl)benzene sulfonate.

  12. Effect of carbonylcyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) on the interaction of 1-anilino-8-naphthalene sulfonate (ANS) with phosphatidylcholine liposomes.

    PubMed

    Cutró, Andrea C; Montich, Guillermo G; Roveri, Oscar A

    2014-04-01

    The weak hydrophobic acid carbonylcyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) is a protonophoric uncoupler of oxidative phosphorylation in mitochondria. It dissipates the electrochemical proton gradient (ΔμH (+)) increasing the mitochondrial oxygen consumption. However, at concentrations higher than 1 μM it exhibits additional effects on mitochondrial energy metabolism, which were tentatively related to modifications of electrical properties of the membrane. Here we describe the effect of FCCP on the binding of 1-anilino-8-naphthalene sulfonate (ANS) to 1, 2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) unilamellar vesicles. FCCP inhibited the binding of ANS to liposomes either in the gel or in the liquid crystalline phase, by increasing the apparent dissociation constant of ANS. Smaller effect on the dissociation constant was observed at high ionic strength, suggesting that the effect of FCCP is through modification of the electrostatic properties of the membrane interface. In addition, FCCP also decreased (approximately 50 %) the quantum yield and increased the intrinsic dissociation constant of membrane-bound ANS, results that suggest that FCCP makes the environment of the ANS binding sites more polar. On those grounds we postulate that the binding of FCCP: i) increases the density of negative charges in the membrane surface; and ii) distorts the phospholipid bilayer, increasing the mobility of the polar headgroups making the ANS binding site more accessible to water. PMID:24570377

  13. Preparation of allenic sulfones and allenes from the selenosulfonation of acetylenes

    SciTech Connect

    Back, T.G.; Krishna, M.V.; Muralidharan, K.R. )

    1989-08-18

    {beta}-(phenylseleno)vinyl sulfones 2 are readily obtained from the free-radical selenosulfonation of acetylenes. Compounds 2 isomerize to allyl sulfones 4 under base-catalyzed conditions in nearly quantitative yield, with high stereoselectivity favoring the Z configuration. Allyl sulfones 4 afford generally high yields of allenic sulfones 1 when subjected to oxidation with m-chloroperbenzoic acid or tert-butyl hydroperoxide, followed by selenoxide syn-elimination. The sulfone-stabilized anion intermediates in the isomerizations of 2 to 4 can be alkylated, deuterated, or silylated in the {alpha}-position prior to oxidation, providing allenic sulfones with an additional {alpha}-substituent. In some cases, spontaneous elimination of the phenylseleno group occurred, producing the allenic sulfone without the need for an oxidation step. Desulfonylation of allyl sulfones 4f, 4c, and 25 with sodium amalgam afforded vinyl selenides that were converted to allenes in moderate to good yields by oxidation-elimination. The copper-catalyzed coupling of allyl sulfones 4 with Grignard reagents comprises an alternative route to vinyl selenide precursors of allenes. These procedures permit the synthesis of various {alpha}- and {gamma}-substituted allenic sulfones and allenes from acetylenes.

  14. Novel sulfonated poly (ether ether ketone)/phosphonic acid-functionalized titania nanohybrid membrane by an in situ method for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Wu, Hong; Cao, Ying; Li, Zhen; He, Guangwei; Jiang, Zhongyi

    2015-01-01

    Sulfonated poly (ether ether ketone)/phosphonic acid-functionalized titania nanohybrid membranes are prepared by an in situ method using titanium tetrachloride (TiCl4) as inorganic precursor and amino trimethylene phosphonic acid (ATMP) as modifier. Phosphonic acid-functionalized titania nanoparticles with a uniform particle size of ∼50 nm are formed and dispersed homogeneously in the SPEEK matrix with good interfacial compatibility. Accordingly, the nanohybrid membranes display remarkably enhanced proton conduction property due to the incorporation of additional sites for proton transport and the formation of well-connected channels by bridging the hydrophilic domains in SPEEK matrix. The nanohybrid membrane with 6 wt. % of phosphonic acid-functionalized titania nanoparticles exhibits the highest proton conductivity of 0.334 S cm-1 at 65 °C and 100% RH, which is 63.7% higher than that of pristine SPEEK membrane. Furthermore, the as-prepared nanohybrid membranes also show elevated thermal and mechanical stabilities as well as decreased methanol permeability.

  15. Evidence for an unrecognized secondary anthropogenic source of organosulfates and sulfonates: gas-phase oxidation of polycyclic aromatic hydrocarbons in the presence of sulfate aerosol.

    PubMed

    Riva, Matthieu; Tomaz, Sophie; Cui, Tianqu; Lin, Ying-Hsuan; Perraudin, Emilie; Gold, Avram; Stone, Elizabeth A; Villenave, Eric; Surratt, Jason D

    2015-06-01

    In the present study, formation of aromatic organosulfates (OSs) from the photo-oxidation of polycyclic aromatic hydrocarbons (PAHs) was investigated. Naphthalene (NAP) and 2-methylnaphthalene (2-MeNAP), two of the most abundant gas-phase PAHs and thought to represent "missing" sources of urban SOA, were photochemically oxidized in an outdoor smog chamber facility in the presence of nonacidified and acidified sulfate seed aerosol. Effects of seed aerosol composition, acidity and relative humidity on OS formation were examined. Chemical characterization of SOA extracts by ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry revealed the formation of OSs and sulfonates from photo-oxidation in the presence of sulfate seed aerosol. Many of the organosulfur compounds identified in the smog chamber extracts were also measured in urban fine aerosol collected at Lahore, Pakistan, and Pasadena, USA, demonstrating that PAH photo-oxidation in the presence of sulfate aerosol is a hitherto unrecognized source of anthropogenic secondary organosulfur compounds, and providing new PAH SOA tracers. PMID:25879928

  16. Sorption of sodium dodecylbenzene sulfonate by montmorillonite.

    PubMed

    Yang, Kun; Zhu, Lizhong; Xing, Baoshan

    2007-01-01

    Sorption of linear alkylbenzene sulfonates by soils and sediments is an important process that may affect their fate, transport, toxicity and their application in remediation of contaminated soil and groundwater. In this study, batch experiments were conducted to elucidate the sorption of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), by montmorillonite. It was observed that: (i) SDBS was sorbed significantly by montmorillonite saturated with Ca(2+), but little by Na-saturated montmorillonite; (ii) the amount of SDBS sorbed by Ca(2+)-montmorillonite was enhanced by NaCl; and (iii) no significant intercalation of SDBS into Ca(2+)-montmorillonite was observed by X-ray diffraction (XRD) analysis. These results indicate that the removal of SDBS by Ca(2+)-montmorillonite was primarily attributed to the precipitation between DBS(-) and Ca(2+) in solution which was released from montmorillonite via cation exchange. These results will help us to understand the sorption behavior and environmental effects of anionic surfactants. PMID:16759775

  17. Sorption of sodium dodecylbenzene sulfonate by montmorillonite.

    PubMed

    Yang, Kun; Zhu, Lizhong; Xing, Baoshan

    2007-01-01

    Sorption of linear alkylbenzene sulfonates by soils and sediments is an important process that may affect their fate, transport, toxicity and their application in remediation of contaminated soil and groundwater. In this study, batch experiments were conducted to elucidate the sorption of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), by montmorillonite. It was observed that: (i) SDBS was sorbed significantly by montmorillonite saturated with Ca(2+), but little by Na-saturated montmorillonite; (ii) the amount of SDBS sorbed by Ca(2+)-montmorillonite was enhanced by NaCl; and (iii) no significant intercalation of SDBS into Ca(2+)-montmorillonite was observed by X-ray diffraction (XRD) analysis. These results indicate that the removal of SDBS by Ca(2+)-montmorillonite was primarily attributed to the precipitation between DBS(-) and Ca(2+) in solution which was released from montmorillonite via cation exchange. These results will help us to understand the sorption behavior and environmental effects of anionic surfactants.

  18. High Lipophilicty of Perfluoroalkyl Carboxylate and Sulfonate

    PubMed Central

    Jing, Ping; Rodgers, Patrick J.; Amemiya, Shigeru

    2009-01-01

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, ∼2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  19. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    NASA Astrophysics Data System (ADS)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  20. Thermal stability of sulfonated polymers

    SciTech Connect

    Audibert, A.; Argillier, J.F.

    1995-11-01

    Polyacrylamides which are used in oil applications i.e. polymer flooding and water based muds, are hydrolyzed versus time and temperature. This leads to a lack of tolerance towards electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structure have been proposed to postpone their thermal stability to higher temperatures. Monomers such as acrylamido methylpropane sulfonate (AMPS) or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis. The aim of this work is to study under controlled conditions, i.e. anaerobic atmosphere, neutral pH, the stability of sulfonated polymers in order to distinguish between hydrolysis and radical degradation reactions. It has been observed that up to 100 C, the AMPS group is stable and protects the acrylamide function from hydrolysis up to 80%. At higher temperature, even the hydrolysis of the AMPS group occurs, giving acrylate and {beta},{beta} dimethyl taurine, with a kinetics that depends on temperature and time. Degradation in terms of molecular weight then occurs indicating that it follows a radical decarboxylation reaction. It can be limited either by the use of free radical scavenger or when the polymer is in the presence of a mineral phase such as bentonite. These results provide valuable data for the determination of the limits of use of sulfonated copolymers and guidelines for optimizing chemical structure of sulfonated polymers used in water based formulation, in particular to enhance their thermal stability.

  1. An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid

    ERIC Educational Resources Information Center

    Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

    2007-01-01

    A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

  2. An alternative standard for Trolox-equivalent antioxidant-capacity estimation based on thiol antioxidants. Comparative 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] decolorization and rotational viscometry study regarding hyaluronan degradation.

    PubMed

    Hrabárová, Eva; Valachová, Katarína; Rapta, Peter; Soltés, Ladislav

    2010-09-01

    Comparison of the effectiveness of antioxidant activity of three thiol compounds, D-penicillamine, reduced L-glutathione, and 1,4-dithioerythritol, expressed as a radical-scavenging capacity based on the two independent methods, namely a decolorization 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay and a rotational viscometry, is reported. Particular concern was focused on the testing of potential free-radical scavenging effects of thiols against hyaluronan degradation, induced by hydroxyl radicals. A promising, solvent-independent, antioxidative function of 1,4-dithioerythritol, comparable to that of a standard compound, Trolox(®), was confirmed by the 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay. The new potential antioxidant 1,4-dithioerythritol exhibited very good solubility in a variety of solvents (e.g., H(2)O, EtOH, and DMSO) and could be widely accepted and used as an effective antioxidant standard instead of a routinely used Trolox(®) on 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay.

  3. Profiling sulfonate ester stability: identification of complementary protecting groups for sulfonates

    PubMed Central

    Miller, Stephen C.

    2010-01-01

    Sulfonation is prized for its ability to impart water-solubility to hydrophobic molecules such as dyes. This modification is usually performed as a final step, since sulfonated molecules are poorly soluble in most organic solvents, which complicates their synthesis and purification. This work compares the intrinsic lability of different sulfonate esters, identifying new sulfonate protecting groups and mild, selective cleavage conditions. PMID:20515067

  4. Sulfone cosurfactants in enhanced oil recovery processes

    SciTech Connect

    Stapp, P. R.

    1984-12-04

    A surfactant system useful for oil recovery consisting essentially of a NaCl, a hydrocarbon sulfonate surfactant, such as a petroleum sulfonate, and a cosurfactant such as a sulfone or sulfolane derivative. In another embodiment, a C/sub 1/ to C/sub 8/ alcohol is additionally present as a cosurfactant.

  5. Safety assessment of xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes as used in cosmetics.

    PubMed

    Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Hill, Ronald; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2011-12-01

    Xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes used in cosmetics as surfactants, hydrotropes, were reviewed in this safety assessment. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Cosmetic Ingredient Review Expert Panel reviewed relevant animal and human data related to these ingredients. The panel concluded that xylene sulfonic acid and alkyl aryl sulfonate hydrotropes are safe as cosmetic ingredients in the present practices of use and concentrations as described in this safety assessment, when formulated to be nonirritating.

  6. 1-Anilino-8-naphthalene sulfonate (ANS) is not a desirable probe for determining the molten globule state of chymopapain.

    PubMed

    Qadeer, Atiyatul; Rabbani, Gulam; Zaidi, Nida; Ahmad, Ejaz; Khan, Javed M; Khan, Rizwan H

    2012-01-01

    The molten globule (MG) state of proteins is widely detected through binding with 1-anilino-8-naphthalene sulphonate (ANS), a fluorescent dye. This strategy is based upon the assumption that when in molten globule state, the exposed hydrophobic clusters of protein are readily bound by the nonpolar anilino-naphthalene moiety of ANS molecules which then produce brilliant fluorescence. In this work, we explored the acid-induced unfolding pathway of chymopapain, a cysteine proteases from Carica papaya, by monitoring the conformational changes over a pH range 1.0-7.4 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). The spectroscopic measurements showed that although maximum ANS fluorescence intensity was observed at pH 1.0, however protein exhibited ∼80% loss of secondary structure which does not comply with the characteristics of a typical MG-state. In contrast at pH 1.5, chymopapain retains substantial amount of secondary structure, disrupted side chain interactions, increased hydrodynamic radii and nearly 30-fold increase in ANS fluorescence with respect to the native state, indicating that MG-state exists at pH 1.5 and not at pH 1.0. ITC measurements revealed that ANS molecules bound to chymopapain via hydrophobic interaction were more at pH 1.5 than at pH 1.0. However, a large number of ANS molecules were also involved in electrostatic interaction with protein at pH 1.0 which, together with hydrophobically interacted molecules, may be responsible for maximum ANS fluorescence. We conclude that maximum ANS-fluorescence alone may not be the criteria for determining the MG of chymopapain. Hence a comprehensive structural analysis of the intermediate is essentially required. PMID:23209794

  7. p-Chlorophenyl methyl sulfone

    Integrated Risk Information System (IRIS)

    p - Chlorophenyl methyl sulfone ; CASRN 98 - 57 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  8. Coarse graining of polystyrene sulfonate

    NASA Astrophysics Data System (ADS)

    Perahia, Dvora; Agrawal, Anupriya; Grest, Gary S.

    2015-03-01

    Capturing large length scales in soft matter while retaining atomistic properties is imperative to computational studies. Here we develop a new coarse-grained model for polystyrene sulfonate (PSS) that often serves as a model system because of its narrow molecular weight distribution and defined degree of sulfonation. Four beads are used to represent polymer where the backbone, the phenyl group, and the sulfonated group are each represented by a different bead and the fourth one represents counterion, which is sodium in our case. Initial atomistic simulations of PSS melt with sulfonation levels of 2-10%, with a dielectric constant ɛ = 1 revealed a ``locked'' phase where motion of the polymer is limited. Dielectric constant of ɛ = 5 was used to accelerate the dynamics. Bonded interactions were obtained using Boltzmann inversion on the bonded distributions extracted from atomistic simulation. Non-bonded interaction of polystyrene monomer was taken from our previous work and potential of mean force was used as the initial guess for interaction of the ionic beads. This set of potential was subsequently iterated to get a good match with radial distribution functions. This potential and its transferability across dielectric constants and temperatures will be presented. Grant DE-SC007908.

  9. Phycotoxicity of linear alkylbenzene sulfonate

    SciTech Connect

    Chawla, G.; Viswanathan, P.N.; Devi, S.

    1988-04-01

    Dose- and time-dependent effects of linear alkylbenzene sulfonate, a major component of synthetic detergent, to the blue-green alga Nostoc muscorum, were studied under laboratory conditions. Toxicity was evident, at doses above 0.001%, from the decrease in biomass, heterocyst number, and protein content and pathomorphological alterations.

  10. Process for sulfonation of gas oils

    SciTech Connect

    Berg, R. C.

    1980-12-23

    A process for the production of oil-soluble sulfonates from a gas oil such as a vacuum gas oil. Water-soluble sulfonic acids are separated from the effluent of the sulfonation zone, and the remainder of the effluent is then passed through a saponification zone to produce oil-soluble sulfonates which are then recovered. The remaining hydrocarbons are fractionated, with the resultant heavy fraction being passed through a reforming zone to produce additional aromatics which are then recycled to the sulfonation zone.

  11. An Evaluation of a Teat Dip with Dodecyl Benzene Sulfonic Acid in Preventing Bovine Mammary Gland Infection from Experimental Exposure to Streptococcus agalactiae and Staphylococcus aureus

    PubMed Central

    Barnum, D. A.; Johnson, R. E.; Brooks, B. W.

    1982-01-01

    The effectiveness of a teat dip with dodecyl benzene sulfonic acid (1.94%) for the prevention of intramammary infections was determined in cows experimentally challenged with Streptococcus agalactiae and Staphylococcus aureus. The infection rates with Streptococcus agalactiae and Staphylococcus aureus were 62.5% and 75% in undipped quarters, 12.5% and 21.5% in dipped quarters with a reduction rate of 80% and 71% respectively. The significance of some findings in relation to mastitis control are discussed. PMID:17422110

  12. Sulfonic acid-functionalized ordered nanoporous Na+-montmorillonite as an efficient, eco-benign, and water-tolerant nanoreactor for chemoselective oxathioacetalization of aldehydes

    NASA Astrophysics Data System (ADS)

    Shirini, Farhad; Atghia, Seyyed Vahid; Mamaghani, Manouchehr

    2013-01-01

    Sulfonic acid-functionalized ordered nanoporous sodium montmorillonite has been found to be a mild and efficient solid acid catalyst for the chemoselective protection of a variety of carbonyl compounds as oxathiolanes in good to excellent yields. The present method offers several advantages such as short reaction times, high yields, simple procedure and mild conditions. Also, the catalyst could be recycled and reused at least for five times without noticeably decreasing the catalytic activity.

  13. Cycling performance and efficiency of sulfonated poly(sulfone) membranes in vanadium redox flow batteries

    SciTech Connect

    Kim, Soowhan; Yan, Jingling; Schwenzer, Birgit; Zhang, Jianlu; Li, Liyu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2010-11-30

    As an alternative to the expensive Nafion® ion exchange membrane, an inexpensive commercially-available Radel® polymer was sulfonated, fabricated into a thin membrane, and evaluated for its performance in a vanadium redox flow battery (VRFB). The sulfonated Radel (S-Radel) membrane showed almost an order of magnitude lower permeability of V (IV) ions (2.07×10-7 cm2/min), compared to Nafion 117 (1.29×10-6 cm2/min), resulting in better coulombic efficiency (~98% vs. 95% at 50 mA/cm2) and lower capacity loss per cycle. Even though the S-Radel membrane had slightly higher membrane resistance, the energy efficiency of the VRFB with the S-Radel membrane was comparable to that of Nafion due to its better coulombic efficiency. The S-Radel membrane exhibited good performance up to 40 cycles, but a decay in performance at later cycles was observed.

  14. 4-Meth-oxy-N-[(4-methyl-phen-yl)sulfon-yl]benzamide including an unknown solvate.

    PubMed

    Sreenivasa, Swamy; Palakshamurthy, Bandrehalli Siddagangaiah; Tonannavar, Jagdish; Jayashree, Yenagi; Sudha, Achar Gurumurthy; Suchetan, Parameshwar Adimoole

    2013-10-19

    In the title compound, C15H15NO4S, the dihedral angle between the benzene rings is 78.62 (16)°. In the crystal, adjacent mol-ecules are linked along the c axis into C(4) chains through strong N-H⋯O hydrogen bonds. Mol-ecules are further connected through C-H⋯O hydrogen bonds into a hexa-meric unit generating an R (6) 6(66) motif. Another C-H⋯O inter-action connects the mol-ecules along the c axis, forming C(5) chains. A region of disordered electron density, most probably disordered methanol-water solvent mol-ecules, was treated with the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. The formula mass and unit-cell characteristics do not take into account this disordered solvent. PMID:24454100

  15. Efficacy of two acidified chlorite postmilking teat disinfectants with sodium dodecylbenzene sulfonic acid on prevention of contagious mastitis using an experimental challenge protocol.

    PubMed

    Oura, L Y; Fox, L K; Warf, C C; Kempt, G K

    2002-01-01

    Two acidified sodium chlorite postmilking teat disinfectants were evaluated for efficacy against Staphylococcus aureus and Streptococcus agalactiae by using National Mastitis Council experimental challenge procedures. The effect of these teat dips on teat skin and teat end condition was also determined. Both dips contained 0.32% sodium chlorite, 1.32% lactic, and 2.5% glycerin. Dips differed in the amount of sodium dodecylbenzene sulfonic acid (0.53 or 0.27%) added as a surfactant. Both dips significantly reduced new intramammary infection (IMI) rates compared with undipped controls. The dip containing 0.53% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 72% and Strep. agalactiae by 75%. The dip containing 0.27% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 100% and by Strep. agalactiae by 88%. Changes in teat skin and teat end condition for treatment and control groups varied in parallel over time. Teats treated with either teat dip had higher mean teat skin and teat end scores than control teats at some weeks. However, teat skin and teat end condition did not tend to change from the start to the completion of the trial. Application of the two new postmilking teat dips was effective in reducing new IMI from contagious mastitis pathogens. (Key words: teat dip, contagious mastitis, chlorous acid) PMID:11860118

  16. Examination of an aloe vera galacturonate polysaccharide capable of in situ gelation for the controlled release of protein therapeutics

    NASA Astrophysics Data System (ADS)

    McConaughy, Shawn David

    fluorescence emission of the probe molecule 1,8-anilino-1-naphthalene sulphonic acid (1,8-ANS) as a function of polymer concentration. Correlations are drawn between viscosity experiments and measurement of zeta potential. Increased degrees of intermolecular interactions are responsible for a shift of Ce to lower polymer concentrations with increasing ionic strength. Additionally, dynamic rheology data are presented highlighting the ability of AvP to form gels at low polymer and calcium ion concentrations, exemplifying the technological potential of this polysaccharide for in-situ drug delivery. In the second section, properties of Aloe vera galacturonate hydrogels formed via Ca2+ crosslinking have been studied in regard to key parameters influencing gel formation including molecular weight, ionic strength and molar ratio of Ca2+ to COO- functionality. Dynamic oscillatory rheology and pulsed field gradient NMR (PFG-NMR) studies have been conducted on hydrogels formed at specified Ca2+ concentrations in the presence and absence of Na+ and K+ ions, in order to assess the feasibility of in situ gelation for controlled delivery of therapeutics. Aqueous Ca2+ concentrations similar to those present in nasal and subcutaneous fluids induce the formation of elastic Aloe vera polysaccharide (AvP) hydrogel networks. By altering the ratio of Ca2+ to COO- functionality, networks may be tailored to provide elastic modulus (G') values between 20 and 20,000 Pa. The Aloe vera polysaccharide exhibits time dependent phase separation in the presence of monovalent electrolytes. Thus the relative rates of calcium induced gelation and phase separation become major considerations when designing a system for in situ delivery applications where both monovalent (Na+, K+) and divalent (Ca2+) ions are present. PFG-NMR and fluorescence microscopy confirm that distinctly different morphologies are present in gels formed in the presence and absence 0.15 M NaCl. Curve fitting of theoretical models to

  17. Oil recovery method utilizing a dialkyl phenol polyethoxy alkyl sulfonate as a solubilizing co-surfactant

    SciTech Connect

    Dunn, N.G.; Hughes, J.W.; Kudchadker, M.V.

    1980-09-02

    The dialkylbenzene polyethoxy alkyl sulfonate is combined with a water soluble petroleum sulfonate surfactant to form an effective surfactant solution that is stable in high salinity environments. The surfactant solution is injected into an underground petroleum reservoir in order to recover crude oil therefrom.

  18. Chemical and Mechanical Degradation of Sulfonated Poly(sulfone) Membranes in Vanadium Redox Flow Batteries

    SciTech Connect

    Kim, Soowhan; Tighe, Timothy B.; Schwenzer, Birgit; Yan, Jingling; Zhang, Jianlu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2011-10-01

    A sulfonated poly(sulfone) (S-Radel{reg_sign}) membrane with high proton conductivity and low vanadium ion diffusion showed high initial performance in a vanadium redox flow battery (VRFB) but suffered damage during charge/discharge cycling. The S-Radel membrane had different degradation behaviors in flow cell cycling and ex-situ vanadium ion immersion tests. The S-Radel membrane immersed in V5+ solution cracked into small pieces, but in the VRFB cell, the membrane underwent internal delamination preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich interface was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the surfaces of the membrane indicated a slightly depressed 1026 cm-1 band corresponding to the sulfonate SO2 stretch for the degraded surface. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer by V5+, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.

  19. p-Sulfonic Acid Calix[4]arene as an Efficient Catalyst for One-Pot Synthesis of Pharmaceutically Significant Coumarin Derivatives under Solvent-Free Condition

    PubMed Central

    Tashakkorian, Hamed; Lakouraj, Moslem Mansour; Rouhi, Mona

    2015-01-01

    One-pot and efficient protocol for preparation of some potent pharmaceutically valuable coumarin derivatives under solvent-free condition via direct coupling using biologically nontoxic organocatalyst, calix[4]arene tetrasulfonic acid (CSA), was introduced. Calix[4]arene sulfonic acid has been incorporated lately as a magnificent and recyclable organocatalyst for the synthesis of some organic compounds. Nontoxicity, solvent-free conditions, good-to-excellent yields for pharmaceutically significant structures, and especially ease of catalyst recovery make this procedure valuable and environmentally benign. PMID:26798517

  20. Copolymers of fluorinated polydienes and sulfonated polystyrene

    DOEpatents

    Mays, Jimmy W.; Gido, Samuel P.; Huang, Tianzi; Hong, Kunlun

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  1. Rapid screening and quantification of sulfonate derivatives in white peony root by UHPLC-MS-MS.

    PubMed

    Yan, Zhixiang; Chen, Chen; Xie, Xiabing; Fu, Bo; Yang, Xinghao

    2012-02-01

    A rapid ultra-high-performance liquid chromatographic-tandem mass spectrometric (UHPLC-MS-MS) method has been developed for rapid screening and quantitative analysis of sulfonate derivatives (SDs) in commercial white peony root. Separation was performed on an Agilent Zorbax Eclipse Plus-C18 column by gradient elution with acetonitrile-0.1% (v/v) formic acid as the mobile phase. In-source fragmentation was used to generate the characteristic fragment ion at m/z 259 and to screen for nine SDs. Detection of these SDs was further performed in multiple reaction monitoring (MRM) mode to improve sensitivity and to quantify the two SDs paeoniflorin sulfonate and benzoylpaeoniflorin sulfonate. The method was validated for specificity, linearity, limits of detection and quantification, precision, accuracy, and matrix effects. Nine commercial white peony root samples were examined by use of this method, which revealed great variety in the paeoniflorin sulfonate and benzoylpaeoniflorin sulfonate content.

  2. Anaerobic degradation of linear alkylbenzene sulfonate.

    PubMed

    Mogensen, Anders S; Haagensen, Frank; Ahring, Birgitte K

    2003-04-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C12 LAS), which show that C12 LAS was biodegradable under methanogenic conditions. Sorption of C12 LAS on sewage sludge was described with a Freundlich isotherm. The C12 LAS sorption was determined with different concentrations of total solids (TS). In the semi-continuously stirred tank reactor, 18% of the added C12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation.

  3. Highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, Hamilton, Ontario, Canada.

    PubMed

    de Solla, S R; De Silva, A O; Letcher, R J

    2012-02-01

    Per- and poly-fluorinated compounds (PFCs), which include perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs) and various precursors, are used in a wide variety of industrial, commercial and domestic products. This includes aqueous film forming foam (AFFF), which is used by military and commercial airports as fire suppressants. In a preliminary assessment prior to this study, very high concentrations (>1 ppm wet weight) of the PFSA, perfluorooctane sulfonate (PFOS), were discovered in the plasma of snapping turtles (Chelydra serpentina) collected in 2008 from Lake Niapenco in southern Ontario, Canada. We presently report on a suite of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, several PFC precursors (e.g. perfluorooctane sulfonamide, PFOSA), and a cyclic perfluorinated acid used in aircraft hydraulic fluid, perfluoroethylcyclohexane sulfonate (PFECHS) in surface water from the Welland River and Lake Niapenco, downstream of the John C. Munro International Airport, Hamilton, Ontario, Canada. Amphipods, shrimp, and water were sampled from the Welland River and Lake Niapenco, as well as local references. The same suite of PFCs in turtle plasma from Lake Niapenco was compared to those from other southern Ontario sites. PFOS dominated the sum PFCs in all substrates (e.g., >99% in plasma of turtles downstream the Hamilton Airport, and 72.1 to 94.1% at all other sites). PFOS averaged 2223(±247.1SE) ng/g in turtle plasma from Lake Niapenco, and ranged from 9.0 to 171.4 elsewhere. Mean PFOS in amphipods and in water were 518.1(±83.8)ng/g and 130.3(±43.6) ng/L downstream of the airport, and 19.1(±2.7) ng/g and 6.8(±0.5) ng/L at reference sites, respectively. Concentrations of selected PFCs declined with distance downstream from the airport. Although there was no known spill event or publicly reported use of AFFF associated with a fire event at the Hamilton airport, the airport is a likely major source of PFC contamination in the Welland River. PMID

  4. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

  5. EVALUATION OF PERFLUOROOCTANE SULFONATE IN THE RAT BRAIN

    EPA Science Inventory

    Perfluorooctane Sulfonate (PFOS) is an environmentally persistent chemical that has been detected in humans and wildlife. PFOS is primarily distributed in liver and blood. The current study evaluated the level of PFOS in the adult and neonatal rat brain and determined whether t...

  6. PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS

    EPA Science Inventory

    PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS. C. Lau, J.R. Thibodeaux, R.G. Hanson, B.E. Gray and J.M. Rogers. Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC.

    PFOS is an environmental contaminant ubiquitously found in h...

  7. Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

    DOEpatents

    Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

    2010-10-19

    An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

  8. Absorption and distribution of perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is found in biosolids, and the application of these biosolids to pastures has raised concerns about human exposure through the accumulation of PFOS in edible tissues of these animals. The United States Department of Agriculture (USDA) h...

  9. Identification of sulfonic acids as efficient ecto-5'-nucleotidase inhibitors.

    PubMed

    Iqbal, Jamshed; Saeed, Aamer; Raza, Rabia; Matin, Abdul; Hameed, Abdul; Furtmann, Norbert; Lecka, Joanna; Sévigny, Jean; Bajorath, Jürgen

    2013-01-01

    Ecto-5'-nucleotidase (CD73) is well known for its implication in cancer. Inhibition of ecto-5'-nucleotidases is thought to provide an attractive approach to cancer therapy. This study identifies sulfonic acid compounds as efficient inhibitors of ecto-5'-nucleotidases. The compounds were tested against recombinant human and rat ecto-5'-nucleotidases. The most potent new sulfonic acid inhibitor 6-amino-4-hydroxynaphthalene-2-sulfonic acid (1) of ecto-5'-nucleotidase had an IC₅₀ of 1.32 ± 0.09 μM for the human and 10.4 ± 3.3 μM for the rat enzyme. Generally, all compounds were more active against the human enzyme. Plausible binding mode models were developed for this new class of inhibitors. Furthermore, several sulfonic acid inhibitors were efficient cytotoxic agents when tested on H157 cancer cell lines. Hence, new ecto-5'-nucleotidases inhibitors displayed significant potential for further development as compounds for anti-cancer therapy.

  10. Use of amine neutralized sulfonated polystyrenes for particle flocculation

    SciTech Connect

    Mintz, D.J.; Peiffer, D.G.; Thaler, W.A.; Duvdevani, I.

    1987-10-20

    A process is described for flocculating solid fines selected from the group consisting of coke films, catalyst fines, synthetic fuel fines, coal fines, and shale fines from a solution comprising the solid fines and an organic liquid which comprises the steps of: (a) adding with mixing about 5 to about 10,000 ppm of the water insoluble unneutralized or neutralized sulfonated polystyrene to the solution wherein the sulfonated polystyrene is dissolved in a dissolving organic liquid at a concentration level of about 0.01 to about 20 weight percent, and has about 0.5 to about 100 mole percent of sulfonate groups; and (b) heating at about 25/sup 0/C to about 350/sup 0/C for about 1 to about 45 minutes the mixture of the solution and the unneutralized or neutralized polystyrene wherein the sulfonated polystrene is absorbed on the surface of the solid fines, and the solid fines collide to form agglomerates which precipitate out of the solution.

  11. Hydrogen-bonding patterns in pyrimethaminium pyridine-3-sulfonate

    PubMed Central

    Nirmalram, Jeyaraman Selvaraj; Thomas Muthiah, Packianathan

    2010-01-01

    In the asymmetric unit of the title salt [systematic name: 2,4-diamino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidin-1-ium pyri­dine-3-sulfonate], C12H14N4Cl+·C5H4NSO3 −, there are two independent pyrimethaminium cations and two 3-pyridine sulfonate anions. Each sulfonate group inter­acts with the corresponding protonated pyrimidine ring through two N—H⋯O hydrogen bonds, forming a cyclic hydrogen-bonded bimolecular R 2 2(8) motif. Even though the primary mode of association is the same, the next higher level of supra­molecular architectures are different due to different hydrogen-bonded networks. In one of the independent molecules in the asymmetric unit, the pyrimethamine cation is paired centrosymmetrically through N—H⋯N hydrogen bonds, generating an R 2 2(8) ring motif. In the other molecule, the pyrimethamine cation does not form any base pairs; instead it forms hydrogen bonds with the 3-pyridine sulfonate anion. The structure is further stabilized by C—H⋯O, C—H⋯N and π–π stacking [centroid–centroid distance = 3.9465 (13) Å] inter­actions. PMID:21588411

  12. Pneumocystis carinii mutations are associated with duration of sulfa or sulfone prophylaxis exposure in AIDS patients.

    PubMed

    Kazanjian, P; Armstrong, W; Hossler, P A; Burman, W; Richardson, J; Lee, C H; Crane, L; Katz, J; Meshnick, S R

    2000-08-01

    This study was conducted to determine whether Pneumocystis carinii dyhydropteroate synthase (DHPS) gene mutations in AIDS patients with P. carinii pneumonia (PCP) are affected by duration of sulfa or sulfone prophylaxis and influence response to sulfa or sulfone therapy. The P. carinii DHPS genes from 97 AIDS patients with PCP between 1991 and 1999 from 4 medical centers were amplified, using polymerase chain reaction (PCR), and sequenced. Mutations were observed in 76% of isolates from patients exposed to sulfa or sulfone prophylaxis compared with 23% of isolates from patients not exposed (P=.001). Duration of prophylaxis increased the risk of mutations (relative risk [RR] for each exposure month, 1.06; P=.02). Twenty-eight percent of patients with mutations failed sulfa or sulfone treatment; mutations increased the risk of sulfa or sulfone treatment failure (RR, 2.1; P=0.01). Thus, an increased duration of sulfa or sulfone prophylaxis increases the chance of developing a P. carinii mutation. The majority of patients with mutations respond to sulfa or sulfone therapy.

  13. Isolation of a novel mutant strain of Saccharomyces cerevisiae by an ethyl methane sulfonate-induced mutagenesis approach as a high producer of bioethanol.

    PubMed

    Mobini-Dehkordi, Mohsen; Nahvi, Iraj; Zarkesh-Esfahani, Hamid; Ghaedi, Kamran; Tavassoli, Manoochehr; Akada, Rinji

    2008-04-01

    In order to obtain mutant strains showing higher bioethanol production than wild-type strains, a commercial Saccharomyces cerevisiae type was subjected to mutagenesis using ethyl methane sulfonate (EMS). After adding EMS to a shaken yeast suspension, the viability of yeast cells was assessed by diluted sample inoculation to solid yeast-extract peptone glucose (YEPG) medium at 15-min intervals. At 45 min, the viability of yeast cells was estimated to be about 40%. Mutagenized cells were recovered from YEPG broth after incubation at 30 degrees C for 18 h. After this period, EMS-treated yeast cells were grown on solid aerobic low-peptone (ALP) medium containing 2-12% (v/v) ethanol. All plates were incubated at 30 degrees C for 2-6 d in order to form colonies. The mutant strains that tolerated high concentrations of ethanol were selected for bioethanol production in microfuge tubes containing fermentation medium. Formation of bioethanol in small tubes was detected by the distillation-colorimetric method. In addition, trehalose content and invertase activity were determined in each mutant strain. Among many isolated mutant strains, there were six isolated colonies that grew on ALP medium supplemented with 10% (v/v) ethanol and one of them produced bioethanol 17.3% more than the wild type.

  14. Novel Ordered Mesoporous Carbon Based Sulfonic Acid as an Efficient Catalyst in the Selective Dehydration of Fructose into 5-HMF: the Role of Solvent and Surface Chemistry.

    PubMed

    Karimi, Babak; Mirzaei, Hamid M; Behzadnia, Hesam; Vali, Hojatollah

    2015-09-01

    Novel ionic liquid derived ordered mesoporous carbons functionalized with sulfonic acid groups IOMC-ArSO3H and GIOMC-ArSO3H were prepared, characterized, and examined in the dehydration reaction of fructose into 5-hydroxymethylfurfural (5-HMF) both in aqueous and nonaqueous systems. To study and correlate the surface properties of these carbocatalysts and some other SBA-15 typed solid acids with 5-HMF yield, hydrophilicity index (H-index) were employed in the fructose dehydration. Our study systematically declared that almost a criterion may be expected for application of solid acids in which by increasing H-index value up to 0.8 the HMF yield enhances accordingly. More increase in H-index up to 1.3 did not change the HMF yield profoundly. Although, it has been shown that the catalyst with larger H-index (∼1.3) resulted in higher activity both in aqueous and 2-propanol systems, during the recycling process deactivation occurs because of more water uptake and the catalysts with optimum amount of H-index (∼0.8) is more robust in the dehydration of fructose.

  15. Use of esters of sulfonic acids as anti-sludge agents during the acidizing of formations containing sludging crude oils

    SciTech Connect

    Looney, J.R.; McDougall, L.A.

    1984-04-10

    An anti-sludge agent useful for acid stimulated hydrocarbon containing formations is an ester of sulfonic acid, e.g. monoethoxylated dodecyl benzene sulfonic acid, preferably used in combination with from 0.1 to 2 parts by weight of a surfactant.

  16. Characterizing hydrocarbon sulfonates and utilization of hydrocarbon sulfonates in oil recovery

    SciTech Connect

    Glinsmann, G.R.; Hedges, J.H.

    1982-05-18

    A method for determining the average equivalent weight of hydrocarbon sulfonates and the optimal salinity and unique salinity of surfactant systems containing such hydrocarbon sulfonates is based on the discovery that the average equivalent weights of hydrocarbon sulfonates vary inversely and linearly as the optimal salinities and unique salinities of surfactant systems containing such hydrocarbon sulfonates vary. Methods of preparing surfactant systems for the displacement of oil from subterranean reservoirs and for the displacement of oil from subterranean reservoirs, based on the above-mentioned relationships, are also disclosed.

  17. Chlorine resistant desalination membranes based on directly sulfonated poly(arylene ether sulfone) copolymers

    DOEpatents

    McGrath, James E.; Park, Ho Bum; Freeman, Benny D.

    2011-10-04

    The present invention provides a membrane, kit, and method of making a hydrophilic-hydrophobic random copolymer membrane. The hydrophilic-hydrophobic random copolymer membrane includes a hydrophilic-hydrophobic random copolymer. The hydrophilic-hydrophobic random copolymer includes one or more hydrophilic monomers having a sulfonated polyarylsulfone monomer and a second monomer and one or more hydrophobic monomers having a non-sulfonated third monomer and a fourth monomer. The sulfonated polyarylsulfone monomer introduces a sulfonate into the hydrophilic-hydrophobic random copolymer prior to polymerization.

  18. Direct methanol fuel cell performance using sulfonated poly (arylene ether sulfone) random copolymers as electrolytes.

    SciTech Connect

    Zawodzinski, T. A. , Jr.; Zelenay, P.; Hickner, M.; Wang, F.; McGrath, James E.; Pivovar, B. S.

    2001-01-01

    Sulfonated poly(arylene ether sulfone) random copolymers are a new series of sulfonic acid containing polymers that have shown promise as fuel cell electrolytes. Here, we report on direct methanol fuel cell (DMFC) performance of this class of polymers at sulfonation levels ranging from 40 to 60% (monomer basis). The DMFC performance of these polymers is compared to that of Nafion 117, the long standing standard in fuel cell testing. These polymers show a higher selectivity for protons over methanol for all the sulfonation levels tested, with the 40% sulfonated polymer showing 2.5 times the selectivity of Nafion. While the higher sulfonated forms (50 and 60%) did show a higher selectivity, only the lower sulfonation levels (40 and 45%) have shown improved performance in DMFC testing. The results of these experiments will be discussed in terms of the relevant test conditions, and experimentally determined membrane properties. The relevant DMFC properties of these polymers will be discussed in terms of sulfonation level and compared to those of Nafion 117.

  19. Synthesis of sulfonate analogs of bile acids.

    PubMed

    Kihira, K; Mikami, T; Ikawa, S; Okamoto, A; Yoshii, M; Miki, S; Mosbach, E H; Hoshita, T

    1992-04-01

    Sulfonate analogs of C23 and C24 bile acids were synthesized from norcholic, norchenodeoxycholic, norursodeoxycholic, nordeoxycholic, norhyodeoxycholic, cholic, deoxycholic, hyodeoxycholic, and lithocholic acids. The principal reactions used were (1) reduction of the bile acids with NaBH4 to the corresponding bile alcohols, (2) selective tosylation of the terminal hydroxyl group, (3) iodination of the tosyl esters with NaI, and (4) treatment of the iodides with Na2SO3 to form the sulfonate analogs of the bile acids. The sulfonate analogs showed polarity similar to that of taurine-conjugated bile acids on thin-layer chromatography. The carbon 13 nuclear magnetic resonance spectral data for the sulfonate analogs were tabulated.

  20. Morphology and Proton Transport in Sulfonated Block Copolymer and Mesoporous Polymer Electrolyte Membranes

    NASA Astrophysics Data System (ADS)

    Chen, Chelsea; Wong, David; Beers, Keith; Balsara, Nitash

    2013-03-01

    In an effort to understand the fundamentals of proton transport in polymer electrolyte membranes (PEMs), we have developed a series of poly(styrene-b-ethylene-b-styrene) (SES) membranes. The SES membranes were subsequently sulfonated to yield proton conducting S-SES membranes. We examine the effects of sulfonation level, temperature and thermal history on the morphology of S-SES membranes in both dry and hydrated states. The effects of these parameters on water uptake and proton transport characteristics of the membranes are also examined. Furthermore, building upon the strategy we deployed in sulfonating the SES membranes, we fabricated mesoporous S-SES membranes, with pores lined up with the proton conducting channels. These membranes have three distinct phases: structural block, proton-conducting block, and void. We examine the effects of pore size, domain structure and sulfonation level on water uptake and proton conductivity of the mesoporous PEMs at different temperatures. This work is funded by Department of Energy.

  1. Effective catalytic conversion of cellulose into high yields of methyl glucosides over sulfonated carbon based catalyst.

    PubMed

    Dora, Sambha; Bhaskar, Thallada; Singh, Rawel; Naik, Desavath Viswanatha; Adhikari, Dilip Kumar

    2012-09-01

    An amorphous carbon based catalyst was prepared by sulfonation of the bio-char obtained from fast pyrolysis (N(2) atm; ≈ 550°C) of biomass. The sulfonated carbon catalyst contained high acidity of 6.28 mmol/g as determined by temperature programmed desorption of ammonia of sulfonated carbon catalyst and exhibited high catalytic performance for the hydrolysis of cellulose. Amorphous carbon based catalyst containing -SO(3)H groups was successfully tested and the complete conversion of cellulose in methanol at moderate temperatures with high yields ca. ≥ 90% of α, β-methyl glucosides in short reaction times was achieved. The methyl glucosides formed in methanol are more stable for further conversion than the products formed in water. The carbon catalyst was demonstrated to be stable for five cycles with slight loss in catalytic activity. The utilization of bio-char as a sulfonated carbon catalyst provides a green and efficient process for cellulose conversion. PMID:22776237

  2. Electric current-producing device having sulfone-based electrolyte

    SciTech Connect

    Angell, Charles Austen; Sun, Xiao-Guang

    2010-11-16

    Electrolytic solvents and applications of such solvents including electric current-producing devices. For example, a solvent can include a sulfone compound of R1--SO2--R2, with R1 being an alkyl group and R2 a partially oxygenated alkyl group, to exhibit high chemical and thermal stability and high oxidation resistance. For another example, a battery can include, between an anode and a cathode, an electrolyte which includes ionic electrolyte salts and a non-aqueous electrolyte solvent which includes a non-symmetrical, non-cyclic sulfone. The sulfone has a formula of R1--SO2--R2, wherein R1 is a linear or branched alkyl or partially or fully fluorinated linear or branched alkyl group having 1 to 7 carbon atoms, and R2 is a linear or branched or partially or fully fluorinated linear or branched oxygen containing alkyl group having 1 to 7 carbon atoms. The electrolyte can include an electrolyte co-solvent and an electrolyte additive for protective layer formation.

  3. Effect of additives on the performance and morphology of sulfonated copoly (phthalazinone biphenyl ether sulfone) composite nanofiltration membranes☆

    NASA Astrophysics Data System (ADS)

    Guan, Shanshan; Zhang, Shouhai; Liu, Peng; Zhang, Guozhen; Jian, Xigao

    2014-03-01

    Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability.

  4. Primary biodegradation of linear alkyltoluene and alkylbenzene sulfonates.

    PubMed

    Singh, M; Satish, S

    1989-01-01

    Studies on the primary biodegradation of linear dodecylbenzene sulfonate, linear dodecyltoluene sulfonate, linear C(10-14) benzene sulfonate, linear C(10-14) toluene sulfonate, commercial samples of linear C(10-14) benzene sulfonate and branched dodecylbenzene sulfonate (DDBS) were carried out using a microbial culture developed from garden soil. Results show that linear alkyl toluene (LAT) is as degradable as linear alkylbenzene (LAB) in 7 days. However, a slower rate of degradation was noted with LAT. Various distributions of the positional isomers of the phenyl ring in the alkane chain of C(10-14) LAB showed no change in the pattern of primary biodegradation.

  5. Characterization of three deoxynivalenol sulfonates formed by reaction of deoxynivalenol with sulfur reagents.

    PubMed

    Schwartz, Heidi Elisabeth; Hametner, Christian; Slavik, Veronika; Greitbauer, Oliver; Bichl, Gerlinde; Kunz-Vekiru, Elisavet; Schatzmayr, Dian; Berthiller, Franz

    2013-09-18

    Reduction of the Fusarium mycotoxin deoxynivalenol (DON) in animal feed by treatment with sodium bisulfite and sodium metabisulfite has been successfully demonstrated in several studies. All of them reported formation of one DON sulfonate of strongly reduced toxicity compared to DON. The starting point of the present work was investigation of different sulfur reagents for reduction of DON. In the course of these experiments, three different DON sulfonates termed DON sulfonate 1 (1), DON sulfonate 2 (2), and DON sulfonate 3 (3) were identified and structurally elucidated by UHPLC-HRMS/MS as well as NMR spectroscopy. Compound 1 is characterized by loss of the epoxide group, and 2 by formation of a hemiketal. Compound 3 is an equilibrating mixture of two isomers, a ketone and a hemiketal. The MS/MS pattern can be used to differentiate the three DON sulfonates, despite their same mass and molecular formula. Investigation of parameters influencing formation and stability of DON sulfonates revealed that rapid formation of 1 and 2 occurs at alkaline pH, whereas at acidic pH, slow formation of 3 takes place, irrespective of the sulfur reagent used. Whereas 1 and 2 are stable across a broad pH range, 3 decomposes to DON, 1, and 2 at alkaline pH. In addition, both 2 and 3 are unstable in solid form. The formation, characterization, and stability of three novel DON sulfonates with respect to results from previous studies are discussed, providing insights of relevance for detoxification of DON-containing animal feed.

  6. Synthesis and characterization of two sulfonated resorcinarenes: a new example of a linear array of sodium centers and macrocycles.

    PubMed

    Sanabria, Edilma; Esteso, Miguel Ángel; Pérez-Redondo, Adrián; Vargas, Edgar; Maldonado, Mauricio

    2015-01-01

    Two sulfonated resorcinarenes were synthesized by reacting C-tetra(butyl) resorcinarene or C-tetra(2-(methylthio)ethyl)resorcinarene with formaldehyde in the presence of sodium sulfite. Their structures were determined via FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. Thermal gravimetric analyses of the derivatives were also carried out and revealed the presence of water molecules in the solid state. The sulfonated product of C-tetra(butyl)resorcinarene was characterized by an X-ray crystal structure determination. The asymmetric unit contains eight molecules of water and two of acetone, and analysis indicated that sulfonated resorcinarene prefers a cone configuration (rccc conformation) in the solid state. In the crystal array, classical hydrogen bond interactions O-H···O and intermolecular contacts were observed. In the crystal packing, a linear array of capsules of sulfonated resorcinarenes was generated for a chain of sodium atoms and sulfonate groups. PMID:26029860

  7. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    PubMed Central

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm−2·mM−1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. PMID:26346240

  8. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite.

    PubMed

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm(-2)·mM(-1). The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

  9. Sulfonation and anticoagulant activity of fungal exocellular β-(1→6)-D-glucan (lasiodiplodan).

    PubMed

    Vasconcelos, Ana Flora D; Dekker, Robert F H; Barbosa, Aneli M; Carbonero, Elaine R; Silveira, Joana L M; Glauser, Bianca; Pereira, Mariana Sá; Corradi da Silva, Maria de Lourdes

    2013-02-15

    An exocellular β-(1→6)-D-glucan (lasiodiplodan) produced by a strain of Lasiodiplodia theobromae (MMLR) grown on sucrose was derivatized by sulfonation to promote anticoagulant activity. The structural features of the sulfonated β-(1→6)-D-glucan were investigated by UV-vis, FT-IR and (13)C NMR spectroscopy, and the anticoagulant activity was investigated by the classical coagulation assays APTT, PT and TT using heparin as standard. The content of sulfur and degree of substitution of the sulfonated glucan was 11.73% and 0.95, respectively. UV spectroscopy showed a band at 261 nm due to the unsaturated bond formed in the sulfonation reaction. Results of FT-IR and (13)C NMR indicated that sulfonyl groups were inserted on the polysaccharide. The sulfonated β-(1→6)-D-glucan presented anticoagulant activity as demonstrated by the increase in dose dependence of APTT and TT, and these actions most likely occurred because of the inserted sulfonate groups on the polysaccharide. The lasiodiplodan did not inhibit the coagulation tests. PMID:23399236

  10. Susceptibility of Candida albicans to new synthetic sulfone derivatives.

    PubMed

    Staniszewska, Monika; Bondaryk, Małgorzata; Ochal, Zbigniew

    2015-02-01

    The influence of halogenated methyl sulfones, i.e. bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named halogenated methyl sulfone 1), dichloromethyl-4-chloro-3-nitrophenyl sulfone (halogenated methyl sulfone 2), and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (halogenated methyl sulfone 3), on cell growth inhibition, aspartic protease gene (SAP4-6) expression, adhesion to epithelium, and filamentation was investigated. Antifungal susceptibility of the halogenated methyl sulfones was determined with the M27-A3 protocol in the range of 16-0.0313 µg/mL. Adherence to Caco-2 cells was performed in 24-well plates; relative quantification was normalized against ACT1 in cells after 18 h of growth in YEPD and on Caco-2 cells. SAP4-6 expression was analyzed using RT-PCR. Structure-activity relationship studies suggested that halogenated methyl sulfone 1 containing bromodichloromethyl or dichloromethyl function at C-4 (halogenated methyl sulfone 2) of the phenyl ring showed the best activity (100% cell inhibition at 0.5 µg/mL), while hydrazine at C-1 (halogenated methyl sulfone 3) reduced the sulfone potential (100% = 4 µg/mL). SAP4-6 were up- or down-regulated depending on the strains' genetic background and the substitutions on the phenyl ring. Halogenated methyl sulfone 2 repressed germination and affected adherence to epithelium (P ≤ 0.05). The tested halogenated methyl sulfones interfered with the adhesion of Candida albicans cells to the epithelial tissues, without affecting their viability after 90 min of incubation. The mode of action of the halogenated methyl sulfones was attributed to the reduced virulence of C. albicans. SAP5 and SAP6 contribute to halogenated methyl sulfones resistance. Thus, halogenated methyl sulfones can inhibit biofilm formation due to their interference with adherence and with the yeast-to-hyphae transition.

  11. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    SciTech Connect

    Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti

    2015-10-15

    Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

  12. Waterflooding employing mixtures of sulfonate surfactants

    SciTech Connect

    Savins, J.G.; Waite, J.M.; Burdyn, R.F.

    1980-11-04

    A new waterflooding process is described in which at least a portion of the injected fluid comprises a viscous aqueous liquid having a monovalent salt salinity within the range of 1.5 to 4.0% by wt and containing first and second sulfonate surfactants. The first surfactant is a petroleum sulfonate having a relatively broad molecular weight distribution and the second surfactant is a synthetic alkyl or alkylaryl sulfonate having a molecular weight distribution narrower than that of the first surfactant. The first and second surfactants are present in the aqueous liquid in relative amounts such that the ratio of the concentration of the first surfactant to the concentration of the second surfactant is within the range of 1:3 to 1:1. The thickened aqueous liquid containing the above described multicomponent surfactant system also contains a water-soluble C3-C6 aliphatic alcohol. 11 claims.

  13. Simulation study of sulfonate cluster swelling in ionomers

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

    2009-12-01

    We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

  14. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    NASA Astrophysics Data System (ADS)

    Stoughton, Hannah L.

    For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

  15. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate,...

  16. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  17. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  18. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate,...

  19. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Trifluoromethane sulfonic acid. 173.395 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst...

  20. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  1. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  2. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Trifluoromethane sulfonic acid. 173.395 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst...

  3. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Trifluoromethane sulfonic acid. 173.395 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst...

  4. An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-immobilized electrode for the simultaneous detection of dopamine and uric acid in the presence of ascorbic acid.

    PubMed

    Chih, Yi-Kai; Yang, Ming-Chang

    2013-06-01

    An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)-immobilized carbon nanotube (CNT) electrode was used to simultaneously detect dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) with differential pulse voltammetry. When ABTS was immobilized onto the CNT electrode in the presence of DA, UA and 100 μM AA, the sensitivity to DA increased from 0.600 (±0.013) to 1.334 (±0.010) μA/μM in the concentration ranges of 0.90-10 μM and 1.87-20 μM, respectively, and the sensitivity to UA increased from 0.030 (±0.005) to 0.078 (±0.006) μA/μM in the concentration ranges of 2.16-240 μM and 3.07-400 μM, respectively. These findings demonstrate that the ABTS-immobilized CNT electrode attained a higher sensitivity to UA and also a wider linear range of concentrations.

  5. Radiation synthesis of eco-friendly water reducing sulfonated starch/acrylic acid hydrogel designed for cement industry

    NASA Astrophysics Data System (ADS)

    Abd El-Rehim, H. A.; Hegazy, El-Sayed A.; Diaa, D. A.

    2013-04-01

    Starch was treated with chlorosulfonic acid to obtain sulfonated starch. Acrylic acid/sulfonated starch semi-interpenetrated network IPN of different compositions was prepared using ionizing radiation. Swelling of prepared IPNs at different environmental conditions was studied. The possible use of sulfonated starch/acrylic acid IPN as a water-retarding agent in the cement industry was investigated. ζ-potential measurements were used to determine the stability of the colloidal cement—SS/AA and cement -poly-naphthalene sulfonic acid (SNF) water retarding mixtures. Sulfonated starch/acrylic acid water-retarding property was influenced by hydrogel concentration and composition. Sulfonated starch/acrylic acid IPN admixture has a great effect on the cement initial setting time. Using 2% of SS/AA or SNF resulted in an increase in initial setting time by 2 and 1 h respectively, if compared with native cement initial setting time. The results showed that the synthetic commercial super-plasticizers could be replaced by an eco-friendly water-retarding sulfonated starch/acrylic acid IPN in the cement industry.

  6. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food... accordance with the following prescribed conditions: (a) For the purpose of this section, the food additive... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lignin sulfonates. 573.600 Section 573.600...

  7. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food... accordance with the following prescribed conditions: (a) For the purpose of this section, the food additive... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lignin sulfonates. 573.600 Section 573.600...

  8. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food... accordance with the following prescribed conditions: (a) For the purpose of this section, the food additive... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lignin sulfonates. 573.600 Section 573.600...

  9. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  10. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    SciTech Connect

    Ames, Richard L.

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate counterparts of similar thickness

  11. Field-amplified sample stacking and nonaqueous capillary electrophoresis determination of complex mixtures of polar aromatic sulfonates.

    PubMed

    Morales, Sergio; Cela, Rafael

    2002-02-01

    Nonaqueous CE and field-amplified sample stacking have been used in the determination of complex mixtures of polar aromatic sulfonates (AS; mainly benzene- and naphthalenesulfonates) of environmental concern. The analytical procedure consists of an on-column aqueous sample enrichment, followed by the nonaqueous electrophoretic determination of stacked aromatic sulfonates. Various organic solvents were used as separation medium, acetonitrile and N-methylformamide gave the best results. Optimum capillary electrophoresis separation is obtained with ammonium acetate (25 mM) dissolved in N-methylformamide-methanol (90:10) as background electrolyte. This combined method was applied to the analysis of surface water samples spiked with selected aromatic sulfonates derivatives.

  12. [New synthesis of the anticoagulant pentasaccharide idraparinux and preparation of its analogues containing sulfonic acid moieties].

    PubMed

    Herczeg, Mihály

    2012-01-01

    Two novel synthetic pathways were elaborated for the preparation of idraparinux, a heparin-related fully O-sulfated, O-methylated anticoagulant pentasaccharide. Both methods based upon a [2+3] block synthesis utilizing the same trisaccharide acceptor which was coupled to either a uronic acid disaccharide donor or its nonoxidized precursor. Two bioisosteric sulfonic acid analogues of idraparinux were also prepared, in which two or three primary sulfate esters were replaced by sodium-sulfonatomethyl moieties. The sulfonic acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic acid esters were found to be excellent donors and acceptors in the glycosylation reactions. The disulfonic-acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more-efficient approach, which involved elongation of the trisaccharide acceptor with a non-oxidized precursor of the glucuronic acid followed by post-glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of the reference compound idraparinux and the new sulfonic acid derivatives revealed that the disulfonate analogue inhibited the blood-coagulation-proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic acid moiety resulted in a notable decrease in the anti-Xa activity.

  13. The enhancement of PCR amplification by low molecular-weight sulfones.

    PubMed

    Chakrabarti, R; Schutt, C E

    2001-08-22

    DNA amplification by polymerase chain reaction (PCR) is frequently complicated by the problems of low yield and specificity, especially when the GC content of the target sequence is high. A common approach to the optimization of such reactions is the addition of small quantities of certain organic chemicals, such as dimethylsulfoxide (DMSO), betaine, polyethylene glycol and formamide, to the reaction mixture. Even in the presence of such additives, however, the amplification of GC-rich templates is often ineffective. In this paper, we introduce a novel class of PCR-enhancing compounds, the low molecular-weight sulfones, that are effective in the optimization of high GC template amplification. We describe here the results of an extensive structure-activity investigation in which we studied the effects of a series of six different sulfones on PCR amplification. We identify two sulfones, sulfolane and methyl sulfone, that are especially potent enhancers of high GC template amplification, and show that these compounds often outperform DMSO and betaine, two of the most effective PCR enhancers currently used. We conclude with a brief discussion of the role that the sulfone functional group may play in such enhancement.

  14. Tin Coatings Electrodeposited from Sulfonic Acid-Based Electrolytes: Tribological Behavior

    NASA Astrophysics Data System (ADS)

    Bengoa, L. N.; Tuckart, W. R.; Zabala, N.; Prieto, G.; Egli, W. A.

    2015-06-01

    A high efficiency methane sulfonic acid electrolyte used for tin electrodeposition was studied, and the properties of the resulting deposits were compared to those of tin coatings obtained from an industrial phenol sulfonic acid electrolyte. Cyclic voltammetry was used to study the effect of organic additives on the reduction process to define the composition of the electrolytic bath. Thick tin electrodeposits were obtained on rotating cylinder steel electrodes, and their surface morphology, preferred crystal orientation, surface roughness, micro hardness, and tribological behavior were measured. Smooth, adherent, and bright tin coatings were obtained from the methane sulfonic acid electrolyte, which differed in morphology and texture from tin electrodeposited from the industrial bath. Influence of organic additives on preferred crystal orientation of the coatings was found to be stronger than changing the supporting sulfonic acid type. Tribological tests showed that the two types of deposits have a similar coefficient of friction. However, tin coatings obtained from methane sulfonic electrolytes presented a lower wear resistance and underwent galling at lower loads.

  15. [New synthesis of the anticoagulant pentasaccharide idraparinux and preparation of its analogues containing sulfonic acid moieties].

    PubMed

    Herczeg, Mihály

    2012-01-01

    Two novel synthetic pathways were elaborated for the preparation of idraparinux, a heparin-related fully O-sulfated, O-methylated anticoagulant pentasaccharide. Both methods based upon a [2+3] block synthesis utilizing the same trisaccharide acceptor which was coupled to either a uronic acid disaccharide donor or its nonoxidized precursor. Two bioisosteric sulfonic acid analogues of idraparinux were also prepared, in which two or three primary sulfate esters were replaced by sodium-sulfonatomethyl moieties. The sulfonic acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic acid esters were found to be excellent donors and acceptors in the glycosylation reactions. The disulfonic-acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more-efficient approach, which involved elongation of the trisaccharide acceptor with a non-oxidized precursor of the glucuronic acid followed by post-glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of the reference compound idraparinux and the new sulfonic acid derivatives revealed that the disulfonate analogue inhibited the blood-coagulation-proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic acid moiety resulted in a notable decrease in the anti-Xa activity. PMID:23230650

  16. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Membrane structure and transport properties

    SciTech Connect

    Sodeye, Akinbode; Huang, Tianzi; Gido, Samuel; Mays, Jimmy

    2011-01-01

    With a view to optimizing morphology and ultimately properties, membranes have been cast from relatively inexpensive block copolymer ionomers of fluorinated polyisoprene-block-sulfonated polystyrene (FISS) with various sulfonation levels, in both the acid form and the cesium neutralized form. The morphology of these membranes was characterized by transmission electron microscopy and ultra-small angle X-ray scattering, as well as water uptake, proton conductivity and methanol permeability within the temperature range from 20 to 60 C. Random phase separated morphologies were obtained for all samples except the cesium sample with 50 mol% sulfonation. The transport properties increased with increasing degree of sulfonation and temperature for all samples. The acid form samples absorbed more water than the cesium samples with a maximum swelling of 595% recorded at 60 C for the acid sample having 50 mol% sulfonation. Methanol permeability for the latter sample was more than an order of magnitude less than for Nafion 112 but so was the proton conductivity within the plane of the membrane at 20 C. Across the plane of the membrane this sample had half the conductivity of Nafion 112 at 60 C.

  17. Highly branched sulfonated poly(fluorenyl ether ketone sulfone)s membrane for energy efficient vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Yin, Bibo; Li, Zhaohua; Dai, Wenjing; Wang, Lei; Yu, Lihong; Xi, Jingyu

    2015-07-01

    A series of highly branched sulfonated poly (fluorenyl ether ketone sulfone)s (HSPAEK) are synthesized by direct polycondensation reactions. The HSPAEK with 8% degree of branching is further investigated as membrane for vanadium redox flow battery (VRFB). The HSPAEK membrane prepared by solution casting method exhibits smooth, dense and tough morphology. It possesses very low VO2+ permeability and high ion selectivity compared to those of Nafion 117 membrane. When applied to VRFB, this novel membrane shows higher coulombic efficiency (CE, 99%) and energy efficiency (EE, 84%) than Nafion 117 membrane (CE, 92% and EE, 78%) at current density of 80 mA cm-2. Besides, the HSPAEK membrane shows super stable CE and EE as well as excellent discharge capacity retention (83%) during 100 cycles life test. After being soaked in 1.5 mol L-1 VO2+ solution for 21 days, the weight loss of HSPAEK membrane and the amount of VO2+ reduced from VO2+ are only 0.26% and 0.7%, respectively, indicating the superior chemical stability of the membrane.

  18. Mechanisms for selective toxicity of fipronil insecticide and its sulfone metabolite and desulfinyl photoproduct.

    PubMed

    Hainzl, D; Cole, L M; Casida, J E

    1998-12-01

    Fipronil, an N-phenylpyrazole with a trifluoromethylsulfinyl substituent, initiated the second generation of insecticides acting at the gamma-aminobutyric acid (GABA) receptor to block the chloride channel. The first generation includes the polychlorocycloalkanes alpha-endosulfan and lindane. In this study, we examine the mechanisms for selective toxicity of the sulfoxide fipronil and its sulfone metabolite and desulfinyl photoproduct relative to their target site interactions in vitro and ex vivo and the importance in fipronil action of biooxidation to the sulfone. Differences in GABA receptor sensitivity, assayed by displacement of 4'-ethynyl-4-n-[2, 3-3H2]propylbicycloorthobenzoate ([3H]EBOB) from the noncompetitive blocker site, appear to be a major factor in fipronil being much more toxic to the insects (housefly and fruit fly) than to the vertebrates (humans, dogs, mice, chickens, quail, and salmon) examined; in insects, the IC50s range from 3 to 12 nM for fipronil and its sulfone and desulfinyl derivatives, while in vertebrates, the IC50 average values are 1103, 175, and 129 nM for fipronil, fipronil sulfone, and desulfinyl fipronil, respectively. The insect relative to the vertebrate specificity decreases in the following order: fipronil > lindane > desulfinyl fipronil > fipronil sulfone > alpha-endosulfan. Ex vivo inhibition of [3H]EBOB binding in mouse brain is similar for fipronil and its sulfone and desulfinyl derivatives at the LD50 dose, but surprisingly, at higher doses fipronil can be lethal without detectably blocking the [3H]EBOB site. The P450 inhibitor piperonyl butoxide, acting in houseflies, increases the metabolic stability and effectiveness of fipronil and the sulfone but not those of the desulfinyl compound, and in mice it completely blocks the sulfoxide to sulfone conversion without altering the poisoning. Thus, the selective toxicity of fipronil and fipronil-derived residues is due in part to the higher potency of the parent compound at

  19. Chronic Exposure of Female Mice to an Environmental Level of Perfluorooctane Sulfonate Suppresses Estrogen Synthesis Through Reduced Histone H3K14 Acetylation of the StAR Promoter Leading to Deficits in Follicular Development and Ovulation.

    PubMed

    Feng, Xuejiao; Wang, Xiaoli; Cao, Xinyuan; Xia, Yankai; Zhou, Rong; Chen, Ling

    2015-12-01

    Perfluorooctane sulfonate (PFOS) at a high dose of 10 mg/kg has been reported to affect the neuroendocrine system and exert toxic effects in rodents. The present study examined the influence of chronic exposure to a low-dose of PFOS (0.1 mg/kg/day) on female reproductive endocrine and function. Herein, we show that adult female mice exposed to PFOS by gavage for 4 months (PFOS-mice) exhibited a prolongation of diestrus without signs of toxic effects. The numbers of mature follicles and corpora luteum were significantly reduced in PFOS-mice with increase of atresic follicles. The levels of serum estrogen (E2) and progesterone at proestrus and diestrus were reduced in PFOS-mice. In comparison with controls, PFOS-mice showed a significant decrease in the levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), and gonadotrophin-releasing hormone, the number of kisspeptin neurons and the level of kiss1 mRNA in anteroventral periventricular nucleus at proestrus but not at diestrus, which could be corrected with the normalization to E2. PFOS-mice did not generate an LH-surge at proestrus, which could be rescued by the application of E2 or kisspeptin-10. Notably, the level of ovarian steroidogenic acute regulatory (StAR) mRNA was decreased in PFOS-mice with the reduction of histone H3K14 acetylation in StAR promoter relative to control mice, whereas the P450scc expression and histone H3K14 acetylation showed no difference between the groups. The present study provides evidence that the chronic exposure to the low-dose of PFOS through selectively reducing histone acetylation of StAR suppresses the biosynthesis of E2 to impair the follicular development and ovulation.

  20. Chronic Exposure of Female Mice to an Environmental Level of Perfluorooctane Sulfonate Suppresses Estrogen Synthesis Through Reduced Histone H3K14 Acetylation of the StAR Promoter Leading to Deficits in Follicular Development and Ovulation.

    PubMed

    Feng, Xuejiao; Wang, Xiaoli; Cao, Xinyuan; Xia, Yankai; Zhou, Rong; Chen, Ling

    2015-12-01

    Perfluorooctane sulfonate (PFOS) at a high dose of 10 mg/kg has been reported to affect the neuroendocrine system and exert toxic effects in rodents. The present study examined the influence of chronic exposure to a low-dose of PFOS (0.1 mg/kg/day) on female reproductive endocrine and function. Herein, we show that adult female mice exposed to PFOS by gavage for 4 months (PFOS-mice) exhibited a prolongation of diestrus without signs of toxic effects. The numbers of mature follicles and corpora luteum were significantly reduced in PFOS-mice with increase of atresic follicles. The levels of serum estrogen (E2) and progesterone at proestrus and diestrus were reduced in PFOS-mice. In comparison with controls, PFOS-mice showed a significant decrease in the levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), and gonadotrophin-releasing hormone, the number of kisspeptin neurons and the level of kiss1 mRNA in anteroventral periventricular nucleus at proestrus but not at diestrus, which could be corrected with the normalization to E2. PFOS-mice did not generate an LH-surge at proestrus, which could be rescued by the application of E2 or kisspeptin-10. Notably, the level of ovarian steroidogenic acute regulatory (StAR) mRNA was decreased in PFOS-mice with the reduction of histone H3K14 acetylation in StAR promoter relative to control mice, whereas the P450scc expression and histone H3K14 acetylation showed no difference between the groups. The present study provides evidence that the chronic exposure to the low-dose of PFOS through selectively reducing histone acetylation of StAR suppresses the biosynthesis of E2 to impair the follicular development and ovulation. PMID:26358002

  1. Characteristics of the uptake of 3,5,3'-triiodo-L-thyronine and L-thyroxine into red blood cells of rainbow trout (Oncorhynchus mykiss).

    PubMed

    McLeese, J M; Eales, J G

    1996-08-01

    The mechanisms of uptake of thyroid hormones (TH) 3,5,3'-triiodo-L-thyronine (T3) and L-thyroxine (T4) by trout red blood cells (RBC) were characterized by coincubating washed RBC with [125I]T3 or [125I]T4 and a variety of inhibitors and potentially competing amino acids and TH analogues. Nonsaturable uptake of both TH was unaffected by almost all agents tested, consistent with a diffusion process. Saturable T3 uptake was unaffected by a major (80%) cyanide- and iodoacetate-induced reduction in RBC nucleotide triphosphate content or by inhibitors of Na+ transport, but was depressed by (i) inhibitors of protein binding (bromosulfophthalein, 8-anilino-1-naphthalene sulfonic acid, phloretin, and 5,5'-diphenylhydantoin, (ii) sulfhydryl blockers (p-hydroxy-mercuribenzoate and N-ethylmaleimide), (iii) endocytotic inhibitors (chloroquine, colchicine, and monodansylcadaverine), (iv) tryptophan and phenylalanine, and (v) certain TH analogues, particularly 3,3',5'-triiodo-L-thyronine (reverse T3). In contrast, saturable T4 uptake was depressed only by inhibitors or protein binding. Cross-competition between T3 and T4 for transport occurred only at highly pharmacologic TH levels. We conclude that T3 and T4 are transported into trout RBC by two separate systems. The relatively slow T4 uptake depends on binding to certain proteins. The much more rapid T3 uptake depends on protein binding, but is Na(+)-independent, and involves a system comparable to the T-system of aromatic amino acid transport. However, participation od receptor-mediated endocytosis cannot be excluded. PMID:8812373

  2. Morphologies in Sulfonated Styrenic Pentablock Copolymer Membranes

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Bramson, Matt; Winey, Karen I.

    2010-03-01

    Membranes of pentablock and triblock copolymers consisting of poly(tert-butyl styrene) (TBS), hydrogenated polyisoprene (HI), and partially sulfonated poly(styrene-ran-styrene sulfonate) (SS) were studied using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The TBS-HI-SS-HI-TBS pentablock and TBS-HI-SS triblock copolymer membranes exhibit anisotropic microphase separated morphologies. Because the pentablock and triblock copolymers can be expected to have complex morphologies, thermal annealing was conducted to promote well-defined morphologies. The annealed membranes exhibit stronger peaks and more high order reflections in SAXS patterns, as well as better defined microstructures in the TEM. Electron microcopy studies with various staining protocols are underway to establish the morphology of the pentablock copolymer membranes including the size and shape of the three microdomains (TBS, HI and SS). We gratefully acknowledge Kraton Polymers, Inc. for materials.

  3. Phase behavior of simple salt tolerant sulfonates

    SciTech Connect

    Barakat, Y.; Fortney, L.N.; Lalanne-Cassou, C.; Schechter, R.S.; Wade, W.H.; Yiv, S.H.

    1982-01-01

    Alkane and /alpha/-olefin sulfonates can be utilized to produce optimal microemulsion formulations which have very high salinity (including divalent ion) tolerance while maintaining large solubilization parameters and low interfacial tensions. Such molecules require elevated temperatures or higher alcohol concentrations to suppress liquid crystal formulation. As found for other species, solubilization is inversely related to width of the three phase regime, and interfacial tension and solubilization are strongly coupled. 18 refs.

  4. Phase behavior of simple salt tolerant sulfonates

    SciTech Connect

    Barakat, Y.; Fortney, L.N.; Lalanne-Cassou, C.; Schechter, R.S.; Wade, W.H.; Yiv, S.H.

    1982-01-01

    Alkane and ..cap alpha..-olefin sulfonates can be utilized to produce optimal microemulsion formulations which have very high salinity (including divalent ion) tolerance while maintaining large solubilization parameters and low interfacial tensions. Such molecules require elevated temperatures or higher alcohol concentrations to suppress liquid crystal formation. As found for other species, solubilization is inversely related to width of the three phase regime, and interfacial tension and solubilization are strongly coupled.

  5. Synthesis of Unsymmetrical Sulfides and Their Oxidation to Sulfones to Discover Potent Antileishmanial Agents.

    PubMed

    Dar, Ajaz A; Enjamuri, Nagasuresh; Shadab, Md; Ali, Nahid; Khan, Abu T

    2015-11-01

    Unsymmetrical sulfides were first synthesized using combinations of a 1,3-dicarbonyl, an aromatic aldehyde and a thiol in the presence of 10 mol % ethanolic piperidine. These sulfides derivatives were subsequently converted into corresponding sulfones via oxidation in the presence of m-chloroperoxybenzoic acid (m-CPBA) at ice-bath to room temperature. The former reaction was achieved at room temperature through one-pot three-component. The later was obtained in good yields using mild reaction conditions with flexibility in choice from a range of substrates. The antimicrobial properties of the newly synthesized sulfone derivatives were investigated against the protozoan parasite, Leishmania donovani, a causative agent of visceral leishmaniasis (VL). Nine sulfone derivatives were found to be efficacious and exhibited significant antimicrobial activity. Further, these compounds were nontoxic on murine peritoneal macrophages thus eliminating potential cytoxicity in the host cells. These compounds may be indicated as potential leads in the treatment of visceral leishmaniasis. PMID:26441303

  6. Nuclear Magnetic Resonance Identification of New Sulfonic Acid Metabolites of Chloroacetanilide Herbicides

    USGS Publications Warehouse

    Morton, M.D.; Walters, F.H.; Aga, D.S.; Thurman, E.M.; Larive, C.K.

    1997-01-01

    The detection of the sulfonic acid metabolites of the chloroacetanilide herbicides acetochlor, alachlor, butachlor, propachlor, and, more recently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation pathway. The identification of these herbicides and their metabolites is important due to growing public awareness and concern about pesticide levels in drinking water. Although these herbicides are regulated, little is known about the fate of their metabolites in soil. The sulfonic acid metabolites were synthesized by reaction of the parent compounds with an excess of sodium sulfite. Acetochlor, alachlor, butachlor, metolachlor, and propachlor and their sulfonic acid metabolites were studied by nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. This paper provides a direct method for the preparation and characterization of these compounds that will be useful in the analysis and study of chloracetanilide herbicides and their metabolites.

  7. Improving the Serum Stability of Site-Specific Antibody Conjugates with Sulfone Linkers

    PubMed Central

    2015-01-01

    Current routes for synthesizing antibody–drug conjugates commonly rely on maleimide linkers to react with cysteine thiols. However, thioether exchange with metabolites and serum proteins can compromise conjugate stability and diminish in vivo efficacy. We report the application of a phenyloxadiazole sulfone linker for the preparation of trastuzumab conjugates. This sulfone linker site-specifically labeled engineered cysteine residues in THIOMABs and improved antibody conjugate stability in human plasma at sites previously shown to be labile for maleimide conjugates. Similarly, sulfone conjugation with selenocysteine in an anti-ROR1 scFv-Fc improved human plasma stability relative to maleimide conjugation. Kinetically controlled labeling of a THIOMAB containing two cysteine substitutions was also achieved, offering a strategy for producing antibody conjugates with expanded valency. PMID:25099687

  8. Transition-metal-free C-S bond formation: a facile access to aryl sulfones from sodium sulfinates via arynes.

    PubMed

    Pandya, Virat G; Mhaske, Santosh B

    2014-07-18

    Sulfones have been attractive targets for synthetic organic chemists owing to their immense applications in medicinal, material, and synthetic chemistry. In this context, an efficient transition-metal-free process has been demonstrated, wherein a broad range of alkyl/aryl/heteroaryl sodium sulfinates react with varyingly substituted aryne precursors (o-silyl aryl triflates) under mild reaction conditions to afford structurally diverse sulfones in good to excellent yields.

  9. Proton conducting sol-gel sulfonated membranes produced from 2-allylphenol, 3-glycidoxypropyl trimethoxysilane and tetraethyl orthosilicate

    NASA Astrophysics Data System (ADS)

    Mosa, J.; Durán, A.; Aparicio, M.

    An important research area in proton exchange membrane fuel cells (PEMFC) is devoted to the development of low cost membranes able to work at temperatures higher than 100 °C. In this work, homogeneous, transparent and crack-free hybrid membranes have been synthesized using tetraethyl orthosilicate (TEOS), 3-glycidoxipropyl trimethoxysilane (GPTMS) and 2-allylphenol (AP) as precursors. The synthesis of proton conducting membranes was performed by a post-sulfonation method using trimethylsilyl chlorosulfonate as a mild sulfonating agent. The water retention properties provided by sulfonate and hydroxyl groups and the high porosity leads to relatively high proton conductivity (maximum values around 1.3 × 10 -3 S cm -1 at 140 °C and 100% RH) for membranes treated at 180 °C and sulfonated for 2 h.

  10. Destruction of gel sulfonated cation-exchangers of the KU-2 type under the influence of hydrogen peroxide

    SciTech Connect

    Roginskaya, B.S.; Zavadovskaya, A.S.; Znamenskii, Yu.P.; Paskhina, N.A.; Dobrova, E.I.

    1988-10-20

    The purpose of this work was to study the mechanism of interaction of Soviet sulfonated cation-exchangers of the KU-2 type with hydrogen peroxide. It is shown that under the influence of hydrogen peroxide sulfonated cation-exchangers begin, after a certain induction period, to lose capacity and to release destruction products into water; the length of the induction period increases with the degree of cross-linking. In a given time of contact between the resin and the solution the degree of destruction falls with increase of cross-linking. The principal product of destruction of sulfonated cation-exchangers is an aromatic sulfonic acid containing oxidized groups in the side chains.

  11. Syntheses, characterizations and crystal structures of two new lead(II) amino and carboxylate-sulfonates with a layered and a pillared layered structure

    NASA Astrophysics Data System (ADS)

    Yuan, Yan-Ping; Mao, Jiang-Gao; Song, Jun-Ling

    2004-03-01

    Reactions of lead(II) acetate with m-aminobenzenesulfonic acid (H L1) and 5-sulfoisophthalic acid (H 3L2) afforded two new lead(II) sulfonates, Pb( L1) 21 and Pb 2( L2)( μ3-OH)(H 2O) 2. In compound 1, the lead(II) ion is eight-coordinated by two sulfonate groups bidentately, two sulfonate groups unidentately and two amino groups from six ligands. Each L1 ligand is tetradentate and bridges with three Pb(II) ions. The interconnection of the Pb(II) ions via bridging sulfonate ligands resulted in <100> and <200> layers. In compound 2, one Pb(II) ion is six-coordinated by a carboxylate group bidentately, by two carboxylate groups unidentately, by a sulfonate oxygen atom and by an OH anion, whereas the other one is six-coordinated by a bidentate chelating carboxylate group, two μ3-OH anions, a sulfonate oxygen atom and an aqua ligand. The interconnection of irregular PbO 6 polyhedra via carboxylate-sulfonate ligands resulted in the formation of a pillared layered structure with the 2D layer being formed; the lead(II) ions, hydroxyl groups, carboxylate and sulfonate groups and the benzene ring as the pillar agent.

  12. Ruthenium(II)-catalyzed oxidative C-H alkenylations of sulfonic acids, sulfonyl chlorides and sulfonamides.

    PubMed

    Ma, Wenbo; Mei, Ruhuai; Tenti, Giammarco; Ackermann, Lutz

    2014-11-10

    Twofold C-H functionalization of aromatic sulfonic acids was achieved with an in situ generated ruthenium(II) catalyst. The optimized cross-dehydrogenative alkenylation protocol proved applicable to differently substituted arenes and a variety of alkenes, including vinyl arenes, sulfones, nitriles and ketones. The robustness of the ruthenium(II) catalyst was demonstrated by the chemoselective oxidative olefination of sulfonamides as well as sulfonyl chlorides. Mechanistic studies provided support for a reversible, acetate-assisted C-H ruthenation, along with a subsequent olefin insertion.

  13. Electrodeposition and characterisation of polypyrroles containing sulfonated carbon nanotubes.

    PubMed

    Lynam, Carol; Wallace, Gordon G; Officer, David L

    2007-10-01

    Using facile diazonium chemistry, sulfonate groups have been covalently attached to single wall carbon nanotubes. The resulting sulfonated tubes form a stable aqueous dispersion in the presence of pyrrole monomer. Subsequent electropolymerisation results in a conductive, electroactive polypyrrole doped with sulfonated tubes being formed at unusually low potentials. The potential of this material as a host matrix for biomolecules has been demonstrated by entrapping horse-radish peroxidase directly in the polypyrrole during composite formation.

  14. Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Tripathi, Bijay P.; Schieda, M.; Shahi, Vinod K.; Nunes, Suzana P.

    Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm -1 at 30 °C and 16.8 × 10 -2 S cm -1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level.

  15. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOEpatents

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  16. Acid-mediated formation of trifluoromethyl sulfonates from sulfonic acids and a hypervalent iodine trifluoromethylating agent.

    PubMed

    Koller, Raffael; Huchet, Quentin; Battaglia, Philip; Welch, Jan M; Togni, Antonio

    2009-10-28

    A variety of sulfonic acids have been trifluoromethylated using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one under mild conditions in good to excellent yields. Initial mechanistic investigations of this reaction show a clean second-order kinetics and only very weak substrate electronic effects.

  17. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    PubMed

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies. PMID:26117498

  18. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    PubMed

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies.

  19. POLYSTYRENE SULFONIC ACID CATALYZED GREENER SYNTHESIS OF HYDRAZONES IN AQUEOUS MEDIUM USING MICROWAVES

    EPA Science Inventory

    An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any organic solvent under mi...

  20. Ruthenium(II) and iridium(III) complexes featuring NHC-sulfonate chelate.

    PubMed

    Rajaraman, A; Sahoo, A R; Hild, F; Fischmeister, C; Achard, M; Bruneau, C

    2015-10-28

    Three new complexes bearing a chelating (κ(2)C,O) NHC-SO3 ligand have been prepared. An original method for the synthesis of the imidazolium-sulfonate NHC precursor is described. The 5-membered ruthena- and irida-cycle containing complexes were fully characterized and evaluated in a series of catalytic transformations involving hydrogen auto-transfer processes.

  1. Effects of prenatal exposure to perfluorooctane sulfonate on the developing lung in the rat

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS), an environmentally stable industrial and household compound, has been detected in human and wildlife sera. Chronic prenatal exposure to PFOS in rodents leads to mortality in newborns within hours to days after birth. We have demonstrated that tr...

  2. Exposure to perfluorooctane sulfonate during pregnancy in rat and mouse. I: maternal and prenatal evaluations

    EPA Science Inventory

    Abstract: The maternal and developmental toxicities of perfluorooctane sulfonate (PFOS, C8F17SO3-) were evaluated in the rat and mouse. PFOS is an environmentally persistent compound used as a surfactant and occurs as a degradation product of both perfluorooctane sulfonyl fluorid...

  3. Nickel-catalyzed synthesis of diarylsulfides and sulfones via C-H bond functionalization of arylamides.

    PubMed

    Reddy, Vutukuri Prakash; Qiu, Renhua; Iwasaki, Takanori; Kambe, Nobuaki

    2015-06-28

    The direct sulfenylation and sulfonylation of (sp(2))C-H bonds of benzamide derivatives were achieved using a Ni catalyst with the aid of an 8-aminoquinoline moiety as a bidentate directing group. These protocols represent a convenient route for the formation of valuable diaryl sulfides and sulfones in moderate to excellent yields. PMID:26006765

  4. Synthesis, Characterization, and Catalytic Activity of Sulfonated Carbon-Based Catalysts Derived From Rubber Tree Leaves and Pulp and Paper Mill Waste

    NASA Astrophysics Data System (ADS)

    Janaun, J.; Sinin, E.; Hiew, S. F.; Kong, A. M. T.; Lahin, F. A.

    2016-06-01

    Sulfonated carbon-based catalysts derived from rubber tree leaves, and pulp and paper mill waste were synthesized and characterized. Three types of catalyst synthesized were sulfonated rubber tree leaves (S-RTL), pyrolysed sludge char (P-SC) and sulfonated sludge char (S-SC). Sulfonated rubber tree leaves (S-RTL) and sulfonated sludge char (S-SC) were prepared through pyrolysis followed by functionalization via sulfonation process whereas, P- SC was only pyrolyzed without sulfonation. The characterization results indicated sulfonic acids, hydroxyl, and carboxyl moieties were detected in S-RTL and S-SC, but no sulfonic acid was detected in P-SC. Total acidity test showed S-RTL had the highest value followed by S-SC and P-SC. The thermal stability of S-RTL and S-SC were up to 230oC as the loss was associated with the decomposition of sulfonic acid group, whereas, P-SC showed higher stability than the S-RTL and S-SC. Morphology analysis showed that S-RTL consisted of an amorphous carbon structure, and a crystalline structure for P-SC and S-SC. Furthermore, traces of metal components were also detected on all of the catalysts. The catalyst catalytic activity was tested through esterification of oleic acid with methanol. The results showed that the reaction using S-RTL catalyst produced the highest conversion (99.9%) followed by P-SC (88.4%) and lastly S-SC (82.7%). The synthesized catalysts showed high potential to be used in biodiesel production.

  5. Hierarchical porous carbon derived from sulfonated pitch for electrical double layer capacitors

    NASA Astrophysics Data System (ADS)

    Guo, Yan; Shi, Zhi-qiang; Chen, Ming-ming; Wang, Cheng-yang

    2014-04-01

    Hierarchical porous carbon (HPC) has been synthesized using sulfonated pitch as a precursor with a simple KOH activation process. Sulfonated pitch has a high content of oxygen-containing groups which enable it to be easily wetted in KOH solution and facilitate the activation process. The effect of the activation agent to precursor ratio on the porosity and the specific surface area is studied by nitrogen adsorption-desorption. A maximum specific surface area of 3548 m2 g-1 is achieved with a KOH to sulfonated pitch ratio of 3 and this produces a structure with micro-, meso- and macropores. Among the various HPC samples, the sample prepared with an activation agent to precursor ratio of 1.5 exhibits the best electrochemical performance as an electrode in an electrical double layer capacitor (EDLC) in 6 M KOH electrolyte. Its gravimetric specific capacitance is 157 F g-1 at a current density of 100 A g-1 and it has a capacitance retention ratio of 98.4% even after 10,000 cycles. The sample also presents outstanding electrochemical performance in 1 M Li2SO4 and 1 M TEA BF4/PC electrolytes. Thus, HPC derived from sulfonated pitch is a promising electrode material for EDLCs.

  6. Synthesis of cyclic sulfones by ring-closing metathesis.

    PubMed

    Yao, Qingwei

    2002-02-01

    A general and highly efficient synthesis of cyclic sulfones based on ring-closing metathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction. PMID:11820896

  7. Synthesis of basic and overbasic sulfonate detergent additives

    SciTech Connect

    Abou El Naga, H.H.; Abd El-Azim, W.M.; Bendary, S.A.; Awad, N.G.

    1993-12-01

    Heavy alkylbenzene, which accumulates as a by-product from linear alkylbenzene synthesis, is evaluated as a starting material for preparation of basic and over basic sulfonate detergent additives. Chemical structure analysis showed that this by-product contains several components in different proportions. Most of these components, as traced via mass spectrometry, showed the presence of paraffinic side chains within the carbon range C{sub 11}--C{sub 22}. Accordingly, sulfonation conditions for it were adjusted to optimize the reaction yield and sulfonic quality. Neutralization of the sulfonic acid was carried out by adding CaO in the presence of methanol as a promoter. Preparation of over basic sulfonate was run via a carbonation process at 55--60 C. Evaluations of synthesized basic calcium sulfonate in comparison to a commercial additive is supported by its efficiency as a detergent additive. The synthesized product has a higher total base number and Ca content than those for the commercial one. On the other hand, evaluation of the synthesized overbasic calcium sulfonate compared with overbasic commercial additives with medium and high alkalinity indicated that the synthesized product can be classified as overbasic calcium sulfonate with medium alkalinity, good dispersive power, and detergent efficiency.

  8. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer, chloro-sulfonated. Ethylene polymer, chlorosulfonated...

  9. Sulfonated Nanoplates in Proton Conducting Membranes for Fuel Cells

    SciTech Connect

    Chen, W.F.; Ni’mah, H.; Yu-Cheng Shen, Y.-C.; Kuo, P.-L.

    2011-09-29

    Surface-functionalized nanoplates are synthesized by anchoring sulfonic acid containing siloxanes on zirconium phosphate, and in turn blended with Nafion to fabricate proton conducting membranes. The effects of these sulfonated nanoplates on proton conduction, hydro-characteristics and fuel cell performance are reported.

  10. Synthesis of cyclic sulfones by ring-closing metathesis.

    PubMed

    Yao, Qingwei

    2002-02-01

    A general and highly efficient synthesis of cyclic sulfones based on ring-closing metathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction.

  11. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  12. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  13. Effective and selective bisphenol A synthesis on a layered silicate with spatially arranged sulfonic acid.

    PubMed

    Ide, Yusuke; Kagawa, Noriko; Itakura, Masaya; Imae, Ichiro; Sadakane, Masahiro; Sano, Tsuneji

    2012-04-01

    The silylated derivatives of a layered alkali silicate, magadiite, modified with propylsulfonic or arylsulfonic acid were synthesized and used as catalysts for an acid-catalyzed condensation of phenol with acetone. The propylsulfonated magadiites with a different amount of the attached silyl group were synthesized by the silylation of the dodecylammonium-exchanged magadiite with the tuned amount of 3-(mercaptopropyl)trimethoxysilane and the subsequent oxidation of the attached thiol to sulfonic acid. The arylsulfonated magadiite was synthesized by the silylation of the dodecylammonium-exchanged magadiite with 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane and the subsequent hydrolysis of the attached sulfonyl chloride to sulfonic acid. The X-ray diffraction (XRD) patterns and elemental mappings of the products, and the photoluminescent spectra of the Eu(3+)-exchanged products suggested that propylsulfonic or arylsulfonic acid was homogeneously distributed in the interlayer space. When all the sulfonated materials were used as an acid catalyst for condensation between phenol and acetone, p,p' bisphenol A selectively formed over the o,p' isomer, and higher yield and selectivity were attained on the catalysts with larger amount of the attached sulfonic acid. When the interlayer space of the propylsulfonated magadiite was expanded by the co-attachment of octadecylsilyl group, lower selectivity was obtained. The arylsulfonated magadiite showed considerably higher p,p' bisphenol A yield than the propylsulfonated magadiites.

  14. Crystal structure of sodium (1S)-d-lyxit-1-yl-sulfonate.

    PubMed

    Haines, Alan H; Hughes, David L

    2016-05-01

    The title compound, Na(+)·C5H11O8S(-) [systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate], is formed by reaction of d-lyxose with sodium bis-ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hy-droxy-methyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexa-coordination of sodium ions by O atoms, three of which are provided by a single d-lyxose-sulfonate unit and the other three by two sulfonate groups and one hy-droxy-methyl group, each from separate units of the adduct. Extensive inter-molecular O-H⋯O hydrogen bonding supplements this bonding network. PMID:27308005

  15. Crystal structure of sodium (1S)-d-lyxit-1-yl­sulfonate

    PubMed Central

    Haines, Alan H.; Hughes, David L.

    2016-01-01

    The title compound, Na+·C5H11O8S− [systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate], is formed by reaction of d-lyxose with sodium bis­ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hy­droxy­methyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexa­coordination of sodium ions by O atoms, three of which are provided by a single d-lyxose–sulfonate unit and the other three by two sulfonate groups and one hy­droxy­methyl group, each from separate units of the adduct. Extensive inter­molecular O—H⋯O hydrogen bonding supplements this bonding network. PMID:27308005

  16. Wine metabolomics reveals new sulfonated products in bottled white wines, promoted by small amounts of oxygen.

    PubMed

    Arapitsas, Panagiotis; Ugliano, Maurizio; Perenzoni, Daniele; Angeli, Andrea; Pangrazzi, Paolo; Mattivi, Fulvio

    2016-01-15

    The impact of minute amounts of oxygen in the headspace on the post-bottling development of wine is generally considered to be very important, since oxygen can either damage or improve the quality of wine. This project aimed to gain new experimental evidence about the chemistry of the interaction between wine and oxygen. The experimental design included 216 bottles of 12 different white wines produced from 6 different cultivars (Inzolia, Muller Thurgau, Chardonnay, Grillo, Traminer and Pinot gris). Half of them were bottled using the standard industrial process with inert headspace and the other half without inert gas and with extra headspace. After 60 days of storage at room temperature, the wines were analysed using an untargeted LC-MS method. The use of a detailed holistic analysis workflow, with several levels of quality control and marker selection, gave 35 metabolites putatively induced by the different amounts of oxygen. These metabolite markers included ascorbic acid, tartaric acid and various sulfonated compounds observed in wine for the first time (e.g. S-sulfonated cysteine, glutathione and pantetheine; and sulfonated indole-3-lactic acid hexoside and tryptophol). The consumption of SO2 mediated by these sulfonation reactions was promoted by the presence of higher levels of oxygen on bottling. PMID:26709023

  17. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    NASA Astrophysics Data System (ADS)

    Chang, Binbin; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-01

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl2 using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl2 at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of -SO3H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N2 adsorption-desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of -SO3H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of -SO3H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and -SO3H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles.

  18. Wine metabolomics reveals new sulfonated products in bottled white wines, promoted by small amounts of oxygen.

    PubMed

    Arapitsas, Panagiotis; Ugliano, Maurizio; Perenzoni, Daniele; Angeli, Andrea; Pangrazzi, Paolo; Mattivi, Fulvio

    2016-01-15

    The impact of minute amounts of oxygen in the headspace on the post-bottling development of wine is generally considered to be very important, since oxygen can either damage or improve the quality of wine. This project aimed to gain new experimental evidence about the chemistry of the interaction between wine and oxygen. The experimental design included 216 bottles of 12 different white wines produced from 6 different cultivars (Inzolia, Muller Thurgau, Chardonnay, Grillo, Traminer and Pinot gris). Half of them were bottled using the standard industrial process with inert headspace and the other half without inert gas and with extra headspace. After 60 days of storage at room temperature, the wines were analysed using an untargeted LC-MS method. The use of a detailed holistic analysis workflow, with several levels of quality control and marker selection, gave 35 metabolites putatively induced by the different amounts of oxygen. These metabolite markers included ascorbic acid, tartaric acid and various sulfonated compounds observed in wine for the first time (e.g. S-sulfonated cysteine, glutathione and pantetheine; and sulfonated indole-3-lactic acid hexoside and tryptophol). The consumption of SO2 mediated by these sulfonation reactions was promoted by the presence of higher levels of oxygen on bottling.

  19. Printing properties of the red reactive dyes with different number sulfonate groups on cotton fabric.

    PubMed

    Xie, Kongliang; Gao, Aiqin; Li, Min; Wang, Xiao

    2014-01-30

    Cellulose fabric is an important printing substrate. Four red azo reactive dyes based on 1-naphthol-8-amino-3,6-disulfonic acid for cotton fabric printing were designed. Their UV-Vis spectra and printing properties for cotton were investigated. The relationship between the chemical structures of the dyes and their printing properties on cotton fabric was discussed. The results show that the color yield (K/S) values of the printed fabrics decreased with the increase of sulfonate groups, but the fixation and penetration of the reactive dyes on cotton fabric increased. The reactive dyes with fewer number sulfonate groups were sensitive to alkaline and urea. Whereas, the reactive dyes with numerous sulfonate groups were not sensitive to urea and had good leveling properties, penetration uniformity, and good wet fastness for cotton fabric. Surface wettability of all cotton fabrics printed with four dyes was excellent. It is possible to print cotton fabric urea-free using the reactive dyes with numerous sulfonate groups.

  20. Chitin nanowhisker-supported sulfonated poly(ether sulfone) proton exchange for fuel cell applications.

    PubMed

    Zhang, Chan; Zhuang, Xupin; Li, Xiaojie; Wang, Wei; Cheng, Bowen; Kang, Weimin; Cai, Zhanjun; Li, Mengqin

    2016-04-20

    To balance the relationship among proton conductivity and mechanic strength of sulfonated poly(ether sulfone) (SPES) membrane, chitin nanowhisker-supported nanocomposite membranes were prepared by incorporating whiskers into SPES. The as-prepared chitin whiskers were prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation of α-chitin from crab shells. The structure and properties of the composite membranes were examined as proton exchange membrane (PEM). Results showed that chitin nanowhiskers were dispersed incompactly in the SPES matrix. Thermal stability, mechanical properties, water uptake and proton conductivity of the nanocomposite films were improved from those of the pure SPES film with increasing whisker content, which ascribed to strong interactions between whiskers and between SPES molecules and chitin whiskers via hydrogen bonding. These indicated that composition of filler and matrix got good properties and whisker-supported membranes are promising materials for PEM.

  1. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane

    NASA Astrophysics Data System (ADS)

    Celso, Fabricio; Mikhailenko, Serguei D.; Rodrigues, Marco A. S.; Mauler, Raquel S.; Kaliaguine, Serge

    2016-02-01

    Composite proton exchange membranes (PEMs) intended for fuel cell applications were prepared by embedding of various amounts of dispersed tri-sulfonic acid ethyl POSS (S-Et-POSS) and tri-sulfonic acid butyl POSS (S-Bu-POSS) in thin films of sulfonated poly ether-ether ketone. The electrical properties of the PEMs were studied by Impedance spectroscopy and it was found that their conductivity σ changes with the filler content following a curve with a maximum. The water uptake of these PEMs showed the same dependence. The investigation of initial isolated S-POSS substances revealed the properties of typical electrolytes, which however in both cases possessed low conductivities of 1. 17 × 10-5 S cm-1 (S-Et-POSS) and 3.52 × 10-5 S cm-1 (S-Bu-POSS). At the same time, the insoluble in water S-POSS was found forming highly conductive interface layer when wetted with liquid water and hence producing a strong positive impact on the conductivity of the composite PEM. Electrical properties of the composites were analysed within the frameworks of effective medium theory and bounding models, allowing to evaluate analytically the range of possible conductivity values. It was found that these approaches produced quite good approximation of the experimental data and constituted a fair basis for interpretation of the observed relationship.

  2. Neutron powder diffraction study of perdeuterodimethyl sulfone.

    PubMed

    Ibberson, R M

    2007-05-01

    The crystal structure of perdeuterodimethyl sulfone, (CD(3))(2)SO(2) or C(2)D(6)O(2)S, has been refined at 4.5 K against high-resolution neutron powder diffraction data. The structure determined previously by Sands [Z. Kristallogr. (1963), 119, 245-251] at ambient temperature is shown to remain down to liquid helium temperature, and at 4.5 K the S-C and S-O bond distances are 1.441 (2) and 1.760 (2) A, respectively. The molecules are distorted tetrahedra with C(2v) point symmetry (crystallographic symmetry m2m for S and m for C, O and one D atom) and are linked through a network of weak hydrogen bonds in the C-centred orthorhombic structure.

  3. Reclamation of waste polystyrene by sulfonation

    SciTech Connect

    Inagaki, Yasuhito; Kuromiya, Miyuki; Noguchi, Tsutomu; Watanabe, Haruo

    1999-06-08

    Waste polystyrene containing additives was converted into a polymeric flocculant by a chemical modification. Specifically, waste polystyrene and waste high-impact polystyrene (HI-PS) containing rubber components or a coloring agent were sulfonated to produce a water-soluble polymer whose molecular weight ranged from 400,000 to 700,000. The polymer provides superior purification of the supernatant after flocculating a kaolin suspension than a conventional polymeric flocculant such as a partially hydrolyzed polyacrylamide (hereafter abbreviate PAA). Moreover, using the polymer and a PAA together provides a higher sedimentation rate and a purer supernatant in the treatment of actual wastewater than using each one separately. A new reclamation technology to convert waste plastic into a functional polymer is reported.

  4. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    SciTech Connect

    Chang, Binbin Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-15

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl{sub 2} using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl{sub 2} at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of –SO{sub 3}H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N{sub 2} adsorption–desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of –SO{sub 3}H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of –SO{sub 3}H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and –SO{sub 3}H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles. - Graphical abstract: Sulfonated porous carbon nanospheres with high surface area and superior catalytic performance were prepared by a facile chemical activation route. - Highlights: • Porous carbon spheres solid acid prepared by a facile chemical activation. • It owns high surface area, superior porosity and uniform spherical morphology. • It possesses

  5. Chemical force titrations of amine- and sulfonic acid-modified poly(dimethylsiloxane).

    PubMed

    Wang, Bin; Oleschuk, Richard D; Horton, J Hugh

    2005-02-15

    Chemical force titrations-measurements of the adhesive interaction between a pair of suitably chemically modified atomic force microscopy (AFM) tip and sample surfaces as a function of pH-have been carried out for various combinations of silanol, amine, carboxylic acid, and sulfonic acid functional groups on both tip and sample. The primary surface material studied was poly(dimethylsiloxane) (PDMS). Surface modification was carried out using a plasma oxidation process to form silanol sites; further modification with amine or sulfonic acid sites was carried out by reaction of the silanol sites with the appropriate trialkoxysilane derivative. AFM tips were also modified using trialkoxysilane compounds. In the cases of tip/sample combinations with the same functional group on each, surface pK(1/2) values could be determined. In several "mixed" tip/sample combinations, a peak appeared in the titration curve midway between the surface pK(1/2) values of the tip and sample, consistent with an ionic H-bonding model for the interactions. The amine/sulfonic acid pair showed more complex behavior; the amine-terminated tip/sulfonic acid-terminated PDMS surface force titration curve consisted of two peaks centered at pH 4 and pH 8. Reversing the tip/sample pair resulted in the peak positions being shifted upward by 1.0 pH unit. The peak appearing at lower pH is assigned to electrostatic interactions between the two oppositely charged surfaces, whereas the higher pH peak is believed to arise due to ionic H-bonding interactions. AFM images show the effects on surface patterning of amine- and sulfonic acid-modified PDMS surfaces that have undergone two different oxidation methods (air plasma oxidation and Tesla coil oxidation). The surface morphologies of freshly prepared and 24 h aged air plasma oxidized PDMS are also discussed in this study.

  6. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  7. Surface adsorption of sulfonated poly(phenylene sulfone)/C14TAB mixtures and its correlation with foam film stability.

    PubMed

    Uhlig, Martin; Miller, Reinhard; Klitzing, Regine von

    2016-07-21

    Polyelectrolyte/surfactant mixtures of rigid monosulfonated poly(phenylene sulfone) (sPSO2-220) and tetradecyl trimethylammonium bromide (C14TAB) were investigated by surface tension, surface elasticity and foam film stability measurements. The results were compared to former measurements of polyelectrolyte/surfactant mixtures containing more flexible polyelectrolytes (PAMPS or PSS and C14TAB). For all polyelectrolyte/surfactant mixtures an increased surface adsorption in comparison to the pure surfactant was detected. Moreover, sPSO2-220/C14TAB mixtures showed a much higher surface activity and foam film stability than mixtures with more flexible polyelectrolytes. The results presented give insight into the surface adsorption and foam film formation of rigid polyelectrolyte/surfactant mixtures. Therefore, this study helps to understand the role of polyelectrolyte backbone rigidity in the formation and stabilization of foam films made from polyelectrolyte/surfactant mixtures.

  8. Synthesis and physical properties of highly sulfonated polyaniline. Technical report

    SciTech Connect

    Wei, X.L.; Bobeczko, C.; Epstein, A.J.

    1996-03-01

    Sulfonated polyaniline (EB-SPAN) is a self-doped conducting polymer. It has a high water solubility and a novel pH-dependent DC conductivity that is of interest for fundamental science and also for applications in such areas as rechargeable battery and pH control technologies. The authors report here the extensive characterization and details of synthesis of a new form of sulfonated polyaniline (LEB-SPAN) which shows novel or significantly improved chemical and physical properties. LEB-SPAN has a much high sulfur to nitrogen ratio (S/N) of N approx. 0.75, 50% larger than that previously reported for EB-SPAN, S/N approx. 0.50. This change in composition leads to significant alteration of the properties including an order of magnitude increase in the room temperature DC conductivity to approx. 1 S./cm, nearly double the solubility in water, and a completely different pH-dependence of the oxidation potential (E1/2). For LEB-SPAN the DC conductivity is unaffected by pH over the range 0 < or = pH < or = 14, strikingly different from the behavior of both parent polyaniline and EB-SPAN which become insulating for pH > or = 3 and pH > or = 7.5; respectively. Temperature-dependent DC conductivity and EPR measurements for LEB-SPAN reveal a lower activation energy for the conductivity and a higher density of states at the Fermi energy as compared with EB-SPAN. The dramatic differences in the pH-dependence of the DC conductivity, cyclic voltammetry (CV), FTIR, and UV-Vis results for LEB-SPAN and EB-SPAN are shown to be a consequence of the much higher S/N ratio in LEB-SPAN.

  9. Electrochemical Windows of Sulfone-Based Electrolytes for High-Voltage Li-Ion Batteries

    SciTech Connect

    Shao, Nan; Sun, Xiao-Guang; Dai, Sheng; Jiang, Deen

    2011-01-01

    Further development of high-voltage lithium-ion batteries requires electrolytes with electrochemical windows greater than 5 V. Sulfone-based electrolytes are promising for such a purpose. Here we compute the electrochemical windows for experimentally tested sulfone electrolytes by different levels of theory in combination with various solvation models. The MP2 method combined with the polarizable continuum model is shown to be the most accurate method to predict oxidation potentials of sulfone-based electrolytes with mean deviation less than 0.29 V. Mulliken charge analysis shows that the oxidation happens on the sulfone group for ethylmethyl sulfone and tetramethylene sulfone, and on the ether group for ether functionalized sulfones. Large electrochemical windows of sulfone-based electrolytes are mainly contributed by the sulfone group in the molecules which helps lower the HOMO level. This study can help understand the voltage limits imposed by the sulfone-based electrolytes and aid in designing new electrolytes with greater electrochemical windows.

  10. Sulfonic Acid- and Lithium Sulfonate-Grafted Poly(Vinylidene Fluoride) Electrospun Mats As Ionic Liquid Host for Electrochromic Device and Lithium-Ion Battery.

    PubMed

    Zhou, Rui; Liu, Wanshuang; Leong, Yew Wei; Xu, Jianwei; Lu, Xuehong

    2015-08-01

    Electrospun polymer nanofibrous mats loaded with ionic liquids (ILs) are promising nonvolatile electrolytes with high ionic conductivity. The large cations of ILs are, however, difficult to diffuse into solid electrodes, making them unappealing for application in some electrochemical devices. To address this issue, a new strategy is used to introduce proton conduction into an IL-based electrolyte. Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) copolymer is functionalized with sulfonic acid through covalent attachment of taurine. The sulfonic acid-grafted P(VDF-HFP) electrospun mats consist of interconnected nanofibers, leading to remarkable improvement in dimensional stability of the mats. IL-based polymer electrolytes are prepared by immersing the modified mats in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF4(-)). It is found that the SO3(-) groups can have Lewis acid-base interactions with the cations (BMIM(+)) of IL to promote the dissociation of ILs, and provide additional proton conduction, resulting in significantly improved ionic conductivity. Using this novel electrolyte, polyaniline-based electrochromic devices show higher transmittance contrast and faster switching behavior. Furthermore, the sulfonic acid-grafted P(VDF-HFP) electrospun mats can also be lithiated, giving additional lithium ion conduction for the IL-based electrolyte, with which Li/LiCoO2 batteries display enhanced C-rate performance.

  11. Synthesis and anticoagulant activity of bioisosteric sulfonic-Acid analogues of the antithrombin-binding pentasaccharide domain of heparin.

    PubMed

    Herczeg, Mihály; Lázár, László; Bereczky, Zsuzsanna; Kövér, Katalin E; Timári, István; Kappelmayer, János; Lipták, András; Antus, Sándor; Borbás, Anikó

    2012-08-20

    Two pentasaccharide sulfonic acids that were related to the antithrombin-binding domain of heparin were prepared, in which two or three primary sulfate esters were replaced by sodium-sulfonatomethyl moieties. The sulfonic-acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic-acid esters were found to be excellent donors and acceptors in the glycosylation reactions. Throughout the synthesis, the hydroxy groups to be methylated were masked in the form of acetates and the hydroxy groups to be sulfated were masked with benzyl groups. The disulfonic-acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more-efficient approach, which involved elongation of the trisaccharide acceptor with a non-oxidized precursor of the glucuronic acid followed by post-glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of these new sulfonic-acid derivatives revealed that the disulfonate analogue inhibited the blood-coagulation-proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic-acid moiety resulted in a notable decrease in the anti-Xa activity. The difference in the biological activity of the disulfonic- and trisulfonic-acid counterparts could be explained by the different conformation of their L-iduronic-acid residues.

  12. Structure-Property Relationships in Sulfonated Pentablock Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Willis, Carl; Winey, Karen I.

    2011-03-01

    Membranes of pentablock copolymers consisting of poly(tert-butyl styrene) (TBS), hydrogenated polyisoprene (HI), and partially sulfonated poly(styrene-ran-styrene sulfonate) (SS) were studied using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The TBS-HI-SS-HI-TBS pentablock copolymer in solution forms spherical micelles with a core of SS and a corona of solvated HI and TBS. The spherical micelles in solution compact as the solvent evaporates and some of SS cores merge to form interconnected SS microdomains without substantially changing their shape. The number of connections increases with the volume fraction of the SS block, which increases with sulfonation level. The structure does not have long-range order, because strong ionic interactions prevent extensive rearrangement. The morphologies of the sulfonated pentablock copolymers will be correlated with their transport properties.

  13. Affinity labelling enzymes with esters of aromatic sulfonic acids

    DOEpatents

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

    Novel esters of aromatic sulfonic acids are disclosed. The specific esters are nitrophenyl p- and m-amidinophenylmethanesulfonate. Also disclosed is a method for specific inactivation of the enzyme, thrombin, employing nitrophenyl p-amidinophenylmethanesulfonate.

  14. Synthesis and characterization of sulfonated single-walled carbon nanotubes and their performance as solid acid catalyst

    NASA Astrophysics Data System (ADS)

    Yu, Hao; Jin, Yuguang; Li, Zhili; Peng, Feng; Wang, Hongjuan

    2008-03-01

    Single-walled carbon nanotubes (SWCNTs) were treated with sulfuric acid at 300 °C to synthesize sulfonated SWCNTs (s-SWCNTs), which were characterized by electron microscopy, infrared, Raman and X-ray photoelectron spectroscopy, and thermo analysis. Compared with activated carbon, more sulfonic acid groups can be introduced onto the surfaces of SWCNTs. The high degree (˜20 wt%) of surface sulfonation led to hydrophilic sidewalls that allows the SWCNTs to be uniformly dispersed in water and organic solvents. The high surface acidity of s-SWCNTs was demonstrated by NH 3 temperature-programmed desorption technique and tested by an acetic acid esterification reaction catalyzed by s-SWCNTs. The results show that the water-dispersive s-SWCNTs are an excellent solid acid catalyst and demonstrate the potential of SWCNTs in catalysis applications.

  15. Design, synthesis, and evaluation of 2 beta-alkenyl penam sulfone acids as inhibitors of beta-lactamases.

    PubMed

    Richter, H G; Angehrn, P; Hubschwerlen, C; Kania, M; Page, M G; Specklin, J L; Winkler, F K

    1996-09-13

    A general method for synthesis of 2 beta-alkenyl penam sulfones has been developed. The new compounds inhibited most of the common types of beta-lactamase. The level of activity depended very strongly on the nature of the substituent in the 2 beta-alkenyl group. The inhibited species formed with the beta-lactamase from Citrobacter freundii 1205 was sufficiently stable for X-ray crystallographic studies. These, together with UV absorption spectroscopy and studies of chemical degradation, suggested a novel reaction mechanism for the new inhibitors that might account for their broad spectrum of action. The (Z)-2 beta-acrylonitrile penam sulfone Ro 48-1220 was the most active inhibitor from this class of compound. The inhibitor enhanced the action of, for example, ceftriaxone against a broad selection of organisms producing beta-lactamases. The organisms included strains of Enterobacteriaceae that produce cephalosporinases, which is an exceptional activity for penam sulfones.

  16. Intercalation of Varied Sulfonates into a Layered MOC: Confinement-Caused Tunable Luminescence and Novel Properties.

    PubMed

    Wen, Yuehong; Sheng, Tianlu; Zhu, Xiaoquan; Zhang, Hao; Zhuo, Chao; Hu, Shengmin; Cao, Wenhai; Wu, Xintao

    2016-04-01

    The pores/channels of porous 3D metal-organic frameworks (MOFs) have been widely applied to incorporate gas, solvent, or organic molecules. On the contrary, the utilization of the interlamellar void of layered metal-organic complexes (MOCs) remains underappreciated, although it is more flexible and available to accommodate molecules with different sizes. In this work, diverse sulfonates have been intercalated purposely into an identical layered MOC, which constructed various novel intercalation compounds possessing fluorescent, white-light emitting, photochromic, homochiral, or nonlinear optical (NLO) properties. With the help of single-crystal X-ray diffraction, their structures and the mutual interactions between the MOC host and the sulfonate guests were characterized. The properties of the guest molecules were tuned and meanwhile some new performances were generated after confining them into the interlayer region. Such a hybrid approach provides an efficient strategy to design and prepare multifunctional materials. PMID:26919304

  17. Acute toxicity to goldfish of mixtures of chloramines, copper, and linear alkylate sulfonate

    SciTech Connect

    Tsai, C.F.; McKee, J.A.

    1980-01-01

    The toxicity to goldfish (Carassius auratus) of mixtures of chloramines, copper, and linear alkylate sulfonate (LAS) was studied by continuous-flow toxicity tests during an exposure period of 96 hours. The individual toxicities of these three chemicals are either additive or synergistic in mixtures, depending on the rate of toxic action of the individual chemical, the toxicity ratio of the chemicals in the mixtures, and the concentration of the mixtures.

  18. Elongational flow of solutions of poly(ethylene oxide) and sulfonated surfactants.

    PubMed

    Smitter, L M; Ruiz, J C; Torres, M E; Müller, A J; Sáez, A E

    2002-07-15

    In this work, the elongational flow behavior of aqueous solutions of poly(ethylene oxide) (PEO) was studied in the presence of sulfonated surfactants. The technique of opposed-jets flow was used to generate an elongational flow field in which pressure drops were measured as a function of strain rates. The surfactants used were sodium dodecyl benzene sulfonate (SDBS) and an alpha-olefin sulfonate (AOS). Solutions of PEO and other flexible polymers exhibit extension thickening in opposed-jets flow due to the formation of transient networks of entangled molecules. This effect is present at concentrations below the static coil overlap concentration, due to the changes in molecular conformation induced by the flow. When SDBS or AOS are added to PEO solutions at low concentrations, the extension thickening weakens due to an increase in PEO intramolecular interactions that lead to coil contraction. This occurs until the surfactant concentration is close to the critical aggregation concentration reported in the literature. Further addition of surfactant induces the formation of intermolecular interactions as the PEO molecules are expanded by the electrostatic repulsion between attached micellar aggregates, with an associated strengthening of extension thickening. Intramolecular effects were not seen beyond a specific PEO concentration.

  19. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification

    PubMed Central

    Muriithi, Beatrice; Loy, Douglas A.

    2016-01-01

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%–30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%–42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes. PMID:26828525

  20. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification.

    PubMed

    Muriithi, Beatrice; Loy, Douglas A

    2016-01-28

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%-30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%-42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes.

  1. Interfacial assignment of branched-alkyl benzene sulfonates: A molecular simulation

    NASA Astrophysics Data System (ADS)

    Liu, Zi-Yu; Wei, Ning; Wang, Ce; Zhou, He; Zhang, Lei; Liao, Qi; Zhang, Lu

    2015-11-01

    A molecular dynamics simulation was conducted to analyze orientations of sodium branched-alkyl benzene sulfonates molecules at nonane/water interface, which is helpful to design optimal surfactant structures to achieve ultralow interfacial tension (IFT). Through the two dimensional density profiles, monolayer collapses are found when surfactant concentration continues to increase. Thus the precise scope of monolayer is certain and orientation can be analyzed. Based on the simulated results, we verdict the interfacial assignment of branched-alkyl benzene sulfonates at the oil-water interface, and discuss the effect of hydrophobic tail structure on surfactant assignment. Bigger hydrophobic size can slow the change rate of surfactant occupied area as steric hindrance, and surfactant meta hydrophobic tails have a stronger tendency to stretch to the oil phase below the collapsed concentration. Furthermore, an interfacial model with reference to collapse, increasing steric hindrance and charge repulsive force between interfacial surfactant molecules, responsible for effecting of surfactant concentration and structure has been supposed.

  2. Synthesis of a sulfonic acid mimetic of the sulfated Lewis A pentasaccharide.

    PubMed

    Jakab, Zsolt; Fekete, Anikó; Csávás, Magdolna; Borbás, Anikó; Lipták, András; Antus, Sándor

    2012-03-01

    The first sulfonic acid mimetic of the sulfated Lewis A pentasaccharide in which the natural L-fucose unit is replaced by a D-arabinose ring was synthesized. Formation of the sulfonic acid moiety at a pentasaccharide level could be successfully achieved by means of introduction of an acetylthio moiety into the terminal D-galactose residue and subsequent oxidation. The equatorial arrangement of the acetylthio group linked to C-3 of the galactose ring could be obtained by double nucleophilic substitutions; efficient formation of the gulo-triflate derivatives required low-power microwave (MW) activation. Oxidation of the acetylthio group was carried out using Oxone in the presence of acetic acid.

  3. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  4. Sulfonate groups grafted on Ti6Al4V favor MC3T3-E1 cell performance in serum free medium conditions.

    PubMed

    Felgueiras, Helena; Migonney, Véronique

    2014-06-01

    Ten years ago, we synthesized "bioactive model polymers" bearing sulfonate groups and proposed a mechanism of their modulation effect at different steps of the cell response. Then, we set up the grafting of polymers bearing sulfonate on Ti6Al4V surfaces by a grafting "from" technique making sure of the creation of covalent bonds between the grafted polymer and the Ti6Al4V surface. We have checked and confirmed the positive effect of grafted sulfonate groups on the osteoblastic cell response in vivo and in vitro but we did not elucidate the mechanism. The aim of this basic work consists first in investigating the role of sulfonate groups in the presence and in the absence of proteins at early stages of the osteointegration process on poly(sodium styrene sulfonate) poly(NaSS) grafted and ungrafted Ti6Al4V surfaces, in vitro. To understand the role of poly(NaSS) grafted chains on osteoblast-like cell response and to confirm/elucidate the importance of fetal bovine serum (FBS) proteins in the culture medium, MC3T3-E1 cells were seeded onto poly(NaSS) grafted and non-grafted Ti6Al4V surfaces. Cultures were carried out in a complete (10% FBS) and in a non-complete medium (without FBS). Cell viability assay, cell attachment number and cell adhesion strength were followed up to 3days of culture. The presence of proteins enhanced cell growth and development whatever the surface and the presence of sulfonate groups enhanced the cell attachment even in the absence of proteins, which suggests and confirms that the sulfonate groups can modify the activity of cells such as the secretion of binding proteins. Statistical differences were found in the attachment strength tests on poly(NaSS) grafted and ungrafted surfaces and showed that the sulfonate groups play an important role in the cell resistance to shear stress. PMID:24863216

  5. High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.

    PubMed

    Jing, Ping; Rodgers, Patrick J; Amemiya, Shigeru

    2009-02-18

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  6. New cation-exchange material based on a sulfonated 3,4-ethylenedioxythiophene monomer

    NASA Astrophysics Data System (ADS)

    Stéphan, O.; Schottland, P.; Le Gall, P.-Y.; Chevrot, C.

    1998-06-01

    The electrochemical oxidation, in aqueous medium, of a 3,4-ethylenedioxythiophene monomer functionalized by a sulfonate group exhibiting cation-exchange properties, allows the synthesis of a new type of water-soluble material. In order to synthesize in water, by oxidative electropolymerization, polymer films of controlled thickness containing attached sulfonate groups, we have investigated the polymerization of the functionalized monomer in the presence of the unsubstituted one without supporting electrolyte. Using an equimolar mixture (0.01 mol/l) of both monomers, copolymers exhibiting cation exchange abilities have been synthesized. As an example, th easy incorporation of hexaamine-ruthenium(III) into one of these copolymers is briefly reported. L'oxydation électrochimique en milieu aqueux d'un monomère de type 3,4- éthylènedioxythiophène fonctionnalisé par un groupement sulfonate permet d'envisager la synthèse d'un nouveau type de polymère hydrosoluble. Afin d'obtenir électrochimiquement en milieu aqueux, un film de polymère d'épaisseur contrôlée contenant des groupements sulfonates, nous avons evisagé de polymériser ce monomère en présence de son homologue non substitué. En partant d'un mélange équimolaire (0.01 mol/l) des deux monomères et en l'absence d'électrolyte support, nous avons synthétisé un matériau possédant des propriétés d'échange de cations. A titre d'exemple, nous présentons brièvement l'incorporation d'un complexe hexaaminé du ruthénium(III) dans un de ces copolymères.

  7. High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.

    PubMed

    Jing, Ping; Rodgers, Patrick J; Amemiya, Shigeru

    2009-02-18

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model.

  8. Destructive effect of polystyrene sulfonate on the structure of hemoproteins

    NASA Astrophysics Data System (ADS)

    Saburova, E. A.; Basova, L. V.; Dybovskaya, Yu. N.; Sukhorukov, B. I.

    2006-08-01

    The mechanism of the destruction of horse heart hemoglobin (Hb) and spermwhale muscle myoglobin (Mb), two hem-containing proteins, by polystyrene sulfonate, an anionic polyelectrolyte, was studied. Measurements of the optical absorption of the prostetic group of the hem in the visible spectrum and of the circular dichroism in the absorption bands of the peptide groups and aromatic amino acid residues demonstrated that the compact structure of both proteins experiences destruction in the presence of polystyrene sulfonate (PSS) at PSS concentrations ten times as low as that of the protein (in wt %) and that the content of α-helix structure in Hb and Mb decreases from 81% in the native state to 43% in their complexes with PSS. The distinctions in the mechanisms of the destruction of Hb and Mb by PSS were found to be as follows: (1) in contrast to Mb, Hb forms insoluble complexes with PSS at low PSS concentrations and (2) Mb-PSS solutions at Mb-to-PSS ratios >1 were found to contain free hems (that absorb at 397 nm), a feature not observed for Hb; the kinetics of the destruction of both the proteins by the polyelectrolyte was demonstrated to be a two-stage process. The first stage of the destruction of Hb (τ ≈ 24.5 s) was found to be four times as slow as that of Mb (τ ≈ 6 s); the second (slow) stage had a halftime of ˜6 h for both the proteins under study. To determine the localization of regions at the protein molecule surface that are capable of binding polyelectrolyte molecules, the distribution of the electrostatic potential over the surface of the Hb and Mb molecules was numerically calculated with the help of the Poisson-Boltzmann equation at pH 6.2 and an ionic strength of 100 mmol/l. Based on experimental and theoretical studies of the mechanism of the interaction of the polyelectrolyte with the proteins, the structural-functional properties of proteins responsible for their destruction by the polyelectrolyte are determined.

  9. Genotoxicity of chryseno[4,5-bcd]thiophene and its sulfone derivative

    SciTech Connect

    Sinsheimer, J.E.; Hooberman, B.H.; Das, S.K.; Savla, P.M.; Ashe, A.J. III )

    1992-01-01

    The authors' recent syntheses of cryseno[4,5-bcd]thiophene together with its potential sulfone metabolite, chryseno[4,5-bcd]thiophene-4,4-dioxide, have made these compounds available for genotoxicity testing. Such toxicity testing is of interest as this thiophene is an isoster of the established carcinogen benzo[a]pyrene and is one of the thiaarenes which are potential environmental contaminants found in fossil fuels. Although the thiophene was less mutagenic than benzo[a]pyrene in Salmonella strains TA98 and TA100 after S9 activation, it exhibited in vivo chromosomal aberration activity equal to that of benzo[a]pyrene in the bone-marrow cells of mice. A reduced activity with Salmonella as well as in the bone-marrow cell assay for the sulfone does not support its role as the key active metabolic intermediate for the genotoxicity of the thiophene. Molecular orbital calculations would be consistent with the concept of activation through a diol-epoxide mechanism and offers an explanation for the reduced genotoxicity of the sulfone via this mechanism. These genotoxicity studies support the concern that sulfur isosters of established carcinogenic polycyclic aromatic hydrocarbons could themselves be toxic. 21 refs., 2 figs., 3 tabs.

  10. Production of Jatropha biodiesel fuel over sulfonic acid-based solid acids.

    PubMed

    Chen, Shih-Yuan; Lao-Ubol, Supranee; Mochizuki, Takehisa; Abe, Yohko; Toba, Makoto; Yoshimura, Yuji

    2014-04-01

    Sulfonic acid-functionalized platelet SBA-15 mesoporous silica with an acid capacity of 2.44mmol H(+) g-cat(-1) (shortly termed 15SA-SBA-15-p) was one-pot synthesized by co-condensation method. When applied as solid acid catalyst in synthesis of Jatropha biodiesel fuel (BDF), the 15SA-SBA-15-p catalyst showed higher activity and resistances to water and free fatty acid (FFA) than commercial sulfonic resins of Amberlyst-15 and SAC-13. For the continuous Jatropha BDF production, a steady 75-78wt% of fatty acid methyl ester (FAME) content was obtained over 15SA-SBA-15-p catalyst at 150°C for 75h, whereas the Amberlyst-15 and SAC-13 catalysts were quickly deactivated due to the decomposition of thermally unstable framework and serious leaching of sulfonic acids. More importantly, the quality, stability and cold flow characteristic of Jatropha BDF synthesized by 15SA-SBA-15-p catalyst were better than those synthesized by Amberlyst-15 and SAC-13 catalysts, making the blending with petro-diesel an easy task.

  11. Synergism between Airborne Singlet Oxygen and a Trisubstituted Olefin Sulfonate for the Inactivation of Bacteria

    PubMed Central

    2015-01-01

    The reactivity of a trisubstituted alkene surfactant (8-methylnon-7-ene-1 sulfonate, 1) to airborne singlet oxygen in a solution containing E. coli was examined. Surfactant 1 was prepared by a Strecker-type reaction of 9-bromo-2-methylnon-2-ene with sodium sulfite. Submicellar concentrations of 1 were used that reacted with singlet oxygen by an “ene” reaction to yield two hydroperoxides (7-hydroperoxy-8-methylnon-8-ene-1 sulfonate and (E)-8-hydroperoxy-8-methylnon-6-ene-1 sulfonate) in a 4:1 ratio. Exchanging the H2O solution for D2O where the lifetime of solution-phase singlet oxygen increases by 20-fold led to an ∼2-fold increase in the yield of hydroperoxides pointing to surface activity of singlet oxygen with the surfactant in a partially solvated state. In this airborne singlet oxygen reaction, E. coli inactivation was monitored in the presence and absence of 1 and by a LIVE/DEAD cell permeabilization assay. It was shown that the surfactant has low dark toxicity with respect to the bacteria, but in the presence of airborne singlet oxygen, it produces a synergistic enhancement of the bacterial inactivation. How the ene-derived surfactant hydroperoxides can provoke 1O2 toxicity and be of general utility is discussed. PMID:24611688

  12. Studies of the condensation of sulfones with ketones and aldehydes.

    PubMed

    Garst, Michael E; Dolby, Lloyd J; Esfandiari, Shervin; Okrent, Rachel A; Avey, Alfred A

    2006-01-20

    [reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF. PMID:16408963

  13. Specifics of solvation of sulfonated polyelectrolytes in water, dimethylmethylphosphonate, and their mixture: A molecular simulation study

    NASA Astrophysics Data System (ADS)

    Vishnyakov, Aleksey; Neimark, Alexander V.

    2008-04-01

    Sulfonated polyelectrolyte membranes (PEMs), such as Nafion and styrene-olefin block copolymers, are explored as permselective membranes for fuel cells as well as suitable barrier materials against chemical agents. The permselective properties of PEM are determined by their microphase segregation into hydrophilic and hydrophobic domains. We performed classical molecular dynamics simulations of solvation of the hydrophilic fragments of PEM exemplified on sulfonated polystyrene (sPS) with potassium, calcium, and aluminum as counterions, in water, phosphor-organic nerve agent simulant dimethylmethylphosphonate (DMMP), and their binary mixture. The force field for the sulfonate group has been developed by optimizing the potential parameters to fit the benzenesulfonate conformations obtained from the density functional theory. For a comparison, we considered perfluorosulfonate oligomers representing fragments of Nafion polymer. We found a noticeable difference between the geometries of the polymer backbone in different solvents. The polymer backbone is stiffer in DMMP for both sPS and Nafion. An anisotropic structuring of the solvent around the phenylsulfonate group is substantially stronger than around the Nafion sidechain due to the rigidity and the anisotropy of the phenylsulfonate group. The counterion significantly affects the conformations of solvated sPS: the rigidity of the backbone increases when potassium or calcium ions are replaced by trivalent aluminum ions.

  14. Development and evaluation of sulfonated polysulfone membranes for the zinc-ferricyanide battery

    NASA Astrophysics Data System (ADS)

    Arnold, C., Jr.; Assink, R. A.

    1985-03-01

    The successful commercialization of the zinc/ferricyanide battery being developed by Lockheed depends in part on the availability of an inexpensive, chemically stable membrane. Other essential membrane properties include low area resistivity (1 - 5 (UC OMEGA) cm(2)) and a low rate of iron permeation (4 x 10(-5) millimoles Fe(cm (2))h). A cast membrane which contained one sulfonate group per repeating unit in th backbone exhibited good stability in the alkaline ferricyanide electrolyte and satisfied the membrane requirements cited above. In ongoing single cell cycling tests, average energy efficiencies of 77% were achieved over 85 charge discharge cycles with this membrane. If sulfonate polysulfone membranes can be mass produced by extrusion, they can be considered as viable candidates to replace the expensive perfluorsulfonate membranes that were used to demonstrate the technical feasibility of the zinc/ferricyanide battery. The feasibility of preparing composite sulfonated polysulfone membranes by impregnation of microporous PTFE was also demonstrated. The manufacture of composite membranes should be possible using chemical coating equipment.

  15. From thiol to sulfonic acid: modeling the oxidation pathway of protein thiols by hydrogen peroxide.

    PubMed

    van Bergen, Laura A H; Roos, Goedele; De Proft, Frank

    2014-08-01

    Hydrogen peroxide is a natural oxidant that can oxidize protein thiols (RSH) via sulfenic acid (RSOH) and sulfinic acid (RSO2H) to sulfonic acid (RSO3H). In this paper, we study the complete anionic and neutral oxidation pathway from thiol to sulfonic acid. Reaction barriers and reaction free energies for all three oxidation steps are computed, both for the isolated substrates and for the substrates in the presence of different model ligands (CH4, H2O, NH3) mimicking the enzymatic environment. We found for all three barriers that the anionic thiolate is more reactive than the neutral thiol. However, the assistance of the environment in the neutral pathway in a solvent-assisted proton-exchange (SAPE) mechanism can lower the reaction barrier noticeably. Polar ligands can decrease the reaction barriers, whereas apolar ligands do not influence the barrier heights. The same holds for the reaction energies: they decrease (become more negative) in the presence of polar ligands whereas apolar ligands do not have an influence. The consistently negative consecutive reaction energies for the oxidation in the anionic pathway when going from thiolate over sulfenic and sulfinic acid to sulfonic acid are in agreement with biological reversibility.

  16. Efficient and selective adsorption of multi-metal ions using sulfonated cellulose as adsorbent.

    PubMed

    Dong, Cuihua; Zhang, Fulong; Pang, Zhiqiang; Yang, Guihua

    2016-10-20

    Contamination of heavy metal in wastewater has caused great concerns on human life and health. Developing an efficient material to eliminate the heavy metal ions has been a popular topic in recent years. In this work, sulfonated cellulose (SC) was explored as efficient adsorbent for metal ions in solution. Thermo gravimetric analyzer (TGA), X-ray diffraction (XRD) and Fourier-transform infrared spectrometer (FTIR) first analyzed the characterizations of SC. Subsequently, effects of solution pH, adsorbent loading, temperature and initial metal ion concentration on adsorption performance were investigated. The results showed that sulfonated modification of cellulose could decrease the crystallinity and thermostability of cellulose. Due to its excellent performance of adsorption to metal ions, SC could reach adsorption equilibrium status within as short as 2min. In multi-component solution, SC can orderly removes Fe(3+), Pb(2+) and Cu(2+) with excellent selectivity and high efficiency. In addition, SC is a kind of green and renewable adsorbent because it can be easily regenerated by treatment with acid or chelating liquors. The mechanism study shows that the sulfonic group play a major role in the adsorption process. PMID:27474562

  17. A potential new metabolite of gamma-hydroxybutyrate: sulfonated gamma-hydroxybutyric acid.

    PubMed

    Hanisch, Stephanie; Stachel, Nicole; Skopp, Gisela

    2016-03-01

    Detection of gamma-hydroxybutyric acid (GHB) became crucial in many clinical and forensic settings due to its increasing use for recreational purposes and drug-facilitated sexual assault. Its narrow window of detection of about 3-12 h in urine represents a major problem. Analogous to ethyl glucuronide, the recently identified GHB-glucuronide exhibits a longer window of detection than the parent drug. It appeared reasonable that a sulfonated metabolite of GHB (GHB-SUL) will also be formed. Due to the lack of an appropriate standard, GHB was incubated with a human liver cytosolic fraction to produce GHB-SUL. Following development of a liquid chromatography/tandem mass spectrometry (LC-MS/MS) assay to measure GHB and GHB-SUL, authentic urine samples (n = 5) were tested for GHB-SUL. These investigations revealed detectable signals of both GHB and GHB-SUL, strongly indicating that GHB is not only glucuronidated but also sulfonated. Given that sulfonated metabolites generally have longer half-life times than the corresponding free drugs, GHB-SUL may serve as a biomarker of GHB misuse along with its glucuronide. PMID:26210636

  18. Photodynamic therapy for experimental intraocular melanoma using chloroaluminum sulfonated phthalocyanine

    SciTech Connect

    Panagopoulos, J.A.; Svitra, P.P.; Puliafito, C.A.; Gragoudas, E.S.

    1989-06-01

    Chloroaluminum sulfonated phthalocyanine (CASPc), a novel photosensitizing dye, was evaluated for treatment of experimental intraocular melanoma in 33 rabbit eyes. An argon ion pumped dye laser, operating at an emission of 675 nm, was used in a nonthermal mode to irradiate iris tumors in rabbits 24 hours after they received in intravenous dye injection (23 eyes). The effects of laser irradiation alone and dye alone were examined in ten control eyes. A threshold tumoricidal dose was established for photodynamic therapy with CASPc and laser irradiation. Vascular occlusion was produced in a well-circumscribed area corresponding to the boundaries of laser irradiation after CASPc injection. Tumors successfully treated with CASPc and laser irradiation were arrested in growth and exhibited no viable tumor cells on histologic examination. Control tumors continued rapid growth, unaffected by dye or laser. Our data indicate that CASPc demonstrates a strong photosensitizing effect on both tumor and normal tissue. These results suggest that CASPc is a potential photosensitizing compound that may be useful in the treatment of choroidal melanoma.

  19. A FACILE ONE-POT SYNTHESIS OF β-KETO SULFONES FROM KETONES UNDER SOLVENT-FREE CONDITIONS

    EPA Science Inventory

    An easy solvent-free method is described for the conversion of ketones into β-keto sulfones in high yields that involves in situ generation of α-tosyloxyketones followed by nucleophilic substitution with sodium arene sulfinate in presence of tetra-butylammonium bromide at ...

  20. Asymmetric synthesis of allylic sulfonic acids: enantio- and regioselective iridium-catalyzed allylations of Na2SO3.

    PubMed

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang; Zhao, Ming-zhu

    2014-12-15

    An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na2 SO3 ) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio- and regioselectivities. (R)-2-Phenyl-2-sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well.

  1. HEPATIC GENE EXPRESSION PROFILING IN PERFLUOROHEXANE SULFONATE-EXPOSED WILD-TYPE AND PPARα-NULL MICE.

    EPA Science Inventory

    Perfluorohexane sulfonate (PFHxS) is one member of a group ofperfluoroakyl acids (PFAAs) presently recognized as widespread environmental contaminants. Like other PFAAs, PFHxS is also commonly found in human serum. Although PFHxS is presumed to be an activator of peroxisome proli...

  2. Asymmetric synthesis of allylic sulfonic acids: enantio- and regioselective iridium-catalyzed allylations of Na2SO3.

    PubMed

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang; Zhao, Ming-zhu

    2014-12-15

    An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na2 SO3 ) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio- and regioselectivities. (R)-2-Phenyl-2-sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well. PMID:25367779

  3. Analysis of metolachlor ethane sulfonic acid chirality in groundwater: A tool for dating groundwater movement in agricultural settings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical chirality of pesticides can be a useful tool for studying environmental processes. The chiral forms of metolachlor ethane sulfonic acid (MESA), an abundant metabolite of metolachlor, and metolachlor were examined over a 6 year period in groundwater and a groundwater-fed stream in a riparia...

  4. Sulfonation Pathway Inhibitors Block Reactivation of Latent HIV-1

    PubMed Central

    Murry, Jeffrey P.; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W.; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A.; Young, John A. T.

    2015-01-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. PMID:25310595

  5. Synthesis and characterization of sulfonated single-walled carbon nanotubes and their performance as solid acid catalyst

    SciTech Connect

    Yu Hao Jin Yuguang; Li Zhili; Peng Feng Wang Hongjuan

    2008-03-15

    Single-walled carbon nanotubes (SWCNTs) were treated with sulfuric acid at 300 deg. C to synthesize sulfonated SWCNTs (s-SWCNTs), which were characterized by electron microscopy, infrared, Raman and X-ray photoelectron spectroscopy, and thermo analysis. Compared with activated carbon, more sulfonic acid groups can be introduced onto the surfaces of SWCNTs. The high degree ({approx}20 wt%) of surface sulfonation led to hydrophilic sidewalls that allows the SWCNTs to be uniformly dispersed in water and organic solvents. The high surface acidity of s-SWCNTs was demonstrated by NH{sub 3} temperature-programmed desorption technique and tested by an acetic acid esterification reaction catalyzed by s-SWCNTs. The results show that the water-dispersive s-SWCNTs are an excellent solid acid catalyst and demonstrate the potential of SWCNTs in catalysis applications. - Graphical abstract: Sulfonated SWCNTs with 20 wt% -SO{sub 2}OH groups were prepared by a high-temperature H{sub 2}SO{sub 4} process, which transformed the hydrophobic surface of pristine SWCNTs to a hydrophilic surface and provided an excellent performance as solid acid catalyst.

  6. Sulfur and hydrogen isotope anomalies in meteorite sulfonic acids.

    PubMed

    Cooper, G W; Thiemens, M H; Jackson, T L; Chang, S

    1997-08-22

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  7. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  8. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart...

  9. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart...

  10. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart...

  11. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart...

  12. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart...

  13. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated sulfonated diphenyl oxide... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and...

  14. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of a substituted sulfonated aryl... New Uses for Specific Chemical Substances § 721.9597 Salt of a substituted sulfonated aryl azo... substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  15. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  16. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Salt of a substituted sulfonated aryl... New Uses for Specific Chemical Substances § 721.9597 Salt of a substituted sulfonated aryl azo... substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  17. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylated sulfonated diphenyl oxide... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and...

  18. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  19. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  20. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  1. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  2. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  3. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  4. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  5. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  6. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  7. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  8. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  9. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  10. 40 CFR 721.10564 - Mixed amino diaryl sulfone isomers (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed amino diaryl sulfone isomers... Specific Chemical Substances § 721.10564 Mixed amino diaryl sulfone isomers (generic). (a) Chemical... as mixed amino diaryl sulfone isomers (PMN P-08-39) is subject to reporting under this section...

  11. 40 CFR 721.10564 - Mixed amino diaryl sulfone isomers (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed amino diaryl sulfone isomers... Specific Chemical Substances § 721.10564 Mixed amino diaryl sulfone isomers (generic). (a) Chemical... as mixed amino diaryl sulfone isomers (PMN P-08-39) is subject to reporting under this section...

  12. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  13. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  14. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  15. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  16. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  17. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  18. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  19. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  20. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  1. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  2. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  3. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  4. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  5. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  6. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  7. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  8. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  9. Surface modification of carbon fibers by a polyether sulfone emulsion sizing for increased interfacial adhesion with polyether sulfone

    NASA Astrophysics Data System (ADS)

    Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang

    2014-10-01

    Interests on carbon fiber-reinforced thermoplastic composites are growing rapidly, but the challenges with poor interfacial adhesion have slowed their adoption. In this work, a polyether sulfone (PES) emulsion sizing was prepared successfully for increased interfacial adhesion of carbon fiber/PES composites. To obtain a high-quality PES emulsion sizing, the key factor, emulsifier concentration, was studied by dynamic light scattering technique. The results demonstrated that the suitable weight ratio of PES to emulsifier was 8:3, and the resulting PES emulsion sizing had an average particle diameter of 117 nm and Zeta potential of -52.6 mV. After sizing, the surface oxygen-containing functional groups, free energy and wettability of carbon fibers increased significantly, which were advantageous to promote molecular-level contact between carbon fiber and PES. Finally, short beam shear tests were performed to evaluate the interfacial adhesion of carbon fiber/PES composites. The results indicated that PES emulsion sizing played a critical role for the enhanced interfacial adhesion in carbon fiber/PES composites, and a 26% increase of interlaminar shear strength was achieved, because of the improved fiber surface wettability and interfacial compatibility between carbon fiber and PES.

  10. Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi, Wijaya, Karna; Budiman, Arief

    2015-12-01

    Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.

  11. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems.

  12. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems. PMID:27389973

  13. Continuous lifetime distributions of β-cyclodextrin-anilinonaphthalene sulfonic acid inclusion complexes.

    PubMed

    Catena, G C; Bright, F V

    1991-03-01

    Fluorescence lifetimes are reported for a series of anilinonaphthalene sulfonate (ANS) probe molecules complexed with β-cyclodextrin (β-CD). The fluorescence decay kinetics are recovered by multifrequency phase and modulation measurements in concert with a global analysis scheme. In all cases studied, a continuous Lorentzian distribution of lifetimes is observed, resulting from the dynamical nature of the ANS-β-CD complex and free ANS. Trends are discussed and comparisons made between bound and free fluorophore and between different isomeric ANS structures.

  14. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  15. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  16. Complexes of poly-N-vinylpyrrolidone with sulfonated tetraphenylporphins

    SciTech Connect

    Kulvelis, Yu. V. Lebedev, V. T.; Toeroek, Gy.; Klyubin, V. V.

    2007-05-15

    The interaction of sulfonated tetraphenylporphins H{sub 2}TPPS{sub 4}(HCl){sub 2} and in CuTPPS{sub 4} with poly-N-vinylpyrrolidone (PVP) is studied using small-angle neutron scattering, dynamic light scattering, visible spectrophotometry, and viscometry. It is shown that porphyrin molecules form complexes with PVP, thus charging the polymeric chain.

  17. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  18. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  19. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for...

  20. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  1. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  2. Isolation of dimethyl sulfone-degrading microorganisms and application to odorless degradation of dimethyl sulfoxide.

    PubMed

    Kino, Kuniki; Murakami-Nitta, Takako; Oishi, Masashi; Ishiguro, Seiji; Kirimura, Kohtaro

    2004-01-01

    With the objective of developing an odorless biodegradation process for dimethyl sulfoxide (DMSO), Hyphomicrobium sp. WU-OM3 was isolated. During the cultivation of strain WU-OM3 cells with 20 mM dimethyl sulfone (DMSO2) as the sole carbon source, DMSO2 was completely consumed within 48 h and sulfate ion accumulated in the culture broth. Methanesulfonate was also detected as an intermediate of DMSO2 degradation. By combining the DMSO-oxidizing microorganism and strain WU-OM3 cells, 0.64 mM (50 mg/l) DMSO was degraded to sulfate ion with 80% molar conversion ratio. PMID:16233595

  3. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants.

    PubMed

    Temmink, H; Klapwijk, Bram

    2004-02-01

    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg l(-1) and at sludge retention times of 10 and 27 days. Effluent and waste sludge concentrations varied between 5 and 10 microg l(-1) and between 37 and 69 microg g(-1) VSS, respectively. In the sludge samples only 2-8% was present as dissolved LAS-C12, whereas the remaining 92-98% was found to be adsorbed to the sludge. In spite of this high degree of sorption, more than 99% of the LAS-C12 load was removed by biodegradation, showing that not only the soluble fraction but also the adsorbed fraction of LAS-C12 is readily available for biodegradation. Sorption and biodegradation of LAS-C12 were also investigated separately. Sorption was an extremely fast and reversible process and could be described by a linear isotherm with a partition coefficient of 3.2 l g(-1) volatile suspended solids. From the results of biodegradation kinetic tests it was concluded that primary biodegradation of LAS-C12 cannot be described by a (growth) Monod model, but a secondary utilisation model should be used instead. The apparent affinity of the sludge to biodegrade LAS-C12 increased when the sludge was loaded with higher influent concentrations of LAS-C12.

  4. Isotopic Measurements of Organic Sulfonates From The Murchison Meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, G. W.; Chang, S.; DeVincenzi, Donald L. (Technical Monitor)

    1995-01-01

    Organic sulfonates and phosphonates have been extracted from the Murchison meteorite for stable isotope measurements. Preliminary stable isotope measurements of individual alkyl sulfonates, R-SO3H (R=C(sub n)H(sub 2n+l)), are shown. These compounds were found in aqueous extracts of Murchison. Both groups show trends similar to other homologous series of organic compounds indigenous to Murchison. Molecular abundances decrease with increasing carbon number, and all possible isomers at each carbon number (through C-4) are present. Carbon isotope measurements of the sulfonates show a decrease in the C-13/C-12 ratio with increasing carbon number. The overall objectives of this project are to obtain dime element carbon, hydrogen, and sulfur - intramolecular isotopic analyses of individual sulfonates, and isotopic measurement of carbon and hydrogen of the phosphonates as a group. The Murchison meteorite is the best characterized carbonaceous chondrite with respect to organic chemistry. The finding of organic sulfonates and phosphonates in Murchison is of interest because they are the first well-characterized series of sulfur and phosphorus containing organic compounds found in meteorites. Also, meteorites, comets, and interplanetary dust particles may have been involved in chemical evolution on the early Earth. Because of the critical role of organic phosphorus and sulfur in all living systems, it is particularly interesting to see examples of abiotic syntheses of these classes of compounds. The study of the isotopic composition of the sulfonates and phosphonates can yield insight into their possible interstellar origin as well as their mechanisms of synthesis in the early solar system. Previous isotopic analyses of other classes of organic compounds indigenous to meteorites, e.g., amino acids, carboxylic acids, and hydrocarbons indicate the possibility that interstellar molecules were incorporated into meteorite parent bodies. In these compounds the ratios of heavy to

  5. ANALYSIS OF SULFONATES IN AQUEOUS SAMPLES BY ION-PAIR LC/ESI-MS/MS WITH IN-SOURCE CID FOR ADDUCT PEAK ELIMINATION

    SciTech Connect

    OUYANG,S.; VAIRAVAMURTHY,M.A.

    1999-06-13

    Determination of low-molecular-weight organic sulfonates (e.g. taurine and cysteic acid) in aqueous solutions is important in many applications of biological, environmental and pharmaceutical sciences. These compounds are difficult to be determined by commonly used reversed-phase liquid chromatographic separation combined with UV-Visible detection because of their high solubility and the lack chromophoric moieties. Here the authors report a method combining ion-pair liquid chromatography and electrospray ionization tandem mass spectrometry (IPLC/ESI-MS/MS)for determining sulfonates. The ability of low-molecular-weight sulfonates to form ion-pairs with quaternary ammonium cations in aqueous solutions allowed LC separation with a C{sub 18} column. Detection of the sulfonates was accomplished with ESI-MS that lends a universal mode of mass detection for polar, water soluble compounds. An in-source collision induced dissociation (CID) was applied to eliminate the adduct peaks in mass spectra. Characteristic marker ions showed in the second stage mass spectra lent a method for identifying sulfonates.

  6. Proparacaine complexation with beta-cyclodextrin and p-sulfonic acid calix[6]arene, as evaluated by varied (1)H-NMR approaches.

    PubMed

    Arantes, Lucas Micquéias; Scarelli, Camilla; Marsaioli, Anita Jocelyne; de Paula, Eneida; Fernandes, Sergio Antonio

    2009-09-01

    This study focused on the use of NMR techniques as a tool for the investigation of complex formation between proparacaine and cyclodextrins (CDs) or p-sulfonic acid calix[6]arene. The pH dependence of the complexation of proparacaine with beta-CD and p-sulfonic acid calix[6]arene was studied and binding constants were determined by (1)H NMR spectroscopy [diffusion-ordered spectroscopy (DOSY)] for the charged and uncharged forms of the local anesthetic in beta-CD and p-sulfonic acid calix[6]arene. The stoichiometries of the complexes was determined and rotating frame Overhauser enhancement spectroscopy (ROESY) 1D experiments revealed details of the molecular insertion of proparacaine into the beta-CD and p-sulfonic acid calix[6]arene cavities. The results unambiguously demonstrate that pH is an important factor for the development of supramolecular architectures based on beta-CD and p-sulfonic acid calix[6]arene as the host molecules. Such host-guest complexes were investigated in view of their potential use as new therapeutic formulations, designed to increase the bioavailability and/or to decrease the systemic toxicity of proparacaine in anesthesia procedures.

  7. Development of a new highly conductive and thermomechanically stable complex membrane based on sulfonated polyimide/ionic liquid for high temperature anhydrous fuel cells

    NASA Astrophysics Data System (ADS)

    Deligöz, Hüseyin; Yılmazoğlu, Mesut

    The paper deals with the synthesis and characterization of a new type of acid doped highly conductive complex membrane based on sulfonated polyimide (sPI) and ionic liquid (IL) for high temperature anhydrous fuel cells. For this purpose, 2,4-diaminobenzene sulfonic acid (2,4-DABSA) is reacted with benzophenontetracarboxylic dianhydride (BTDA) to yield sulfonated poly(amic acid) (sPAA) intermediate. Subsequently, IL is added into sPAA to form an interaction between sulfonic acid and imidazolium group of IL followed by acid doping. The ionic conductivity of acid doped sPI/IL complex polymer membrane is higher than that of IL containing composite membranes reported in the literature (5.59 × 10 -2 S cm -1 at 180 °C). Furthermore, dynamic mechanical analysis (DMA) results of acid doped sPI/IL complex membrane show that the mechanical strength of the complex product is slightly changed until 350 °C due to the formation of ionic interactions between sulfonic acid groups of sPI and imidazolium groups of IL. Consequently, the ionic interaction not only provides high ionic conductivity with excellent thermomechanical properties (the storage module of 0.91 GPa at 300 °C) but also results in a positive effect in long term conductivity stability by blocking IL migration through the membrane.

  8. Discovery of novel sulfonated small molecules that inhibit vascular tube formation

    PubMed Central

    Raman, Karthik; Karuturi, Rajesh; Swarup, Vimal P.; Desai, Umesh R.; Kuberan, Balagurunathan

    2012-01-01

    Tumor-associated angiogenesis is a complex process that involves the interplay among several molecular players such as cell-surface heparan sulfate proteoglycans, vascular endothelial growth factors and their cognate receptors. PI-88, a highly sulfonated oligosaccharide, has been shown to have potent anti-angiogenic activity and is currently in clinical trials. However, one of the major drawbacks of large oligosaccharides such as PI-88 is that their synthesis often requires numerous complex synthetic steps. In this study, several novel polysulfonated small molecule carbohydrate mimetics, which can easily be synthesized in fewer steps, are identified as promising inhibitors of angiogenesis in an in vitro tube formation assay. PMID:22627041

  9. Low-molecular-weight sulfonates, a major substrate for sulfate reducers in marine microbial mats.

    PubMed

    Visscher, P T; Gritzer, R F; Leadbetter, E R

    1999-08-01

    Several low-molecular-weight sulfonates were added to microbial mat slurries to investigate their effects on sulfate reduction. Instantaneous production of sulfide occurred after taurine and cysteate were added to all of the microbial mats tested. The rates of production in the presence of taurine and cysteate were 35 and 24 microM HS(-) h(-1) in a stromatolite mat, 38 and 36 microM HS(-) h(-1) in a salt pond mat, and 27 and 18 microM HS(-) h(-1) in a salt marsh mat, respectively. The traditionally used substrates lactate and acetate stimulated the rate of sulfide production 3 to 10 times more than taurine and cysteate stimulated the rate of sulfide production in all mats, but when ethanol, glycolate, and glutamate were added to stromatolite mat slurries, the resulting increases were similar to the increases observed with taurine and cysteate. Isethionate, sulfosuccinate, and sulfobenzoate were tested only with the stromatolite mat slurry, and these compounds had much smaller effects on sulfide production. Addition of molybdate resulted in a greater inhibitory effect on acetate and lactate utilization than on sulfonate use, suggesting that different metabolic pathways were involved. In all of the mats tested taurine and cysteate were present in the pore water at nanomolar to micromolar concentrations. An enrichment culture from the stromatolite mat was obtained on cysteate in a medium lacking sulfate and incubated anaerobically. The rate of cysteate consumption by this enrichment culture was 1.6 pmol cell(-1) h(-1). Compared to the results of slurry studies, this rate suggests that organisms with properties similar to the properties of this enrichment culture are a major constituent of the sulfidogenic population. In addition, taurine was consumed at some of highest dilutions obtained from most-probable-number enrichment cultures obtained from stromatolite samples. Based on our comparison of the sulfide production rates found in various mats, low

  10. Improved oral absorption of cilostazol via sulfonate salt formation with mesylate and besylate

    PubMed Central

    Seo, Jae Hong; Park, Jung Bae; Choi, Woong-Kee; Park, Sunhwa; Sung, Yun Jin; Oh, Euichaul; Bae, Soo Kyung

    2015-01-01

    Objective Cilostazol is a Biopharmaceutical Classification System class II drug with low solubility and high permeability, so its oral absorption is variable and incomplete. The aim of this study was to prepare two sulfonate salts of cilostazol to increase the dissolution and hence the oral bioavailability of cilostazol. Methods Cilostazol mesylate and cilostazol besylate were synthesized from cilostazol by acid addition reaction with methane sulfonic acid and benzene sulfonic acid, respectively. The salt preparations were characterized by nuclear magnetic resonance spectroscopy. The water contents, hygroscopicity, stress stability, and photostability of the two cilostazol salts were also determined. The dissolution profiles in various pH conditions and pharmacokinetic studies in rats were compared with those of cilostazol-free base. Results The two cilostazol salts exhibited good physicochemical properties, such as nonhygroscopicity, stress stability, and photostability, which make it suitable for the preparation of pharmaceutical formulations. Both cilostazol mesylate and cilostazol besylate showed significantly improved dissolution rate and extent of drug release in the pH range 1.2–6.8 compared to the cilostazol-free base. In addition, after oral administration to rats, cilostazol mesylate and cilostazol besylate showed increases in Cmax and AUCt of approximately 3.65- and 2.87-fold and 3.88- and 2.94-fold, respectively, compared to cilostazol-free base. Conclusion This study showed that two novel salts of cilostazol, such as cilostazol mesylate and cilostazol besylate, could be used to enhance its oral absorption. The findings warrant further preclinical and clinical studies on cilostazol mesylate and cilostazol besylate at doses lower than the usually recommended dosage, so that it can be established as an alternative to the marketed cilostazol tablet. PMID:26251575

  11. Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

    PubMed Central

    Pop, Flavia

    2015-01-01

    Summary Enantiopure (R,R) and (S,S)-dimethyl-bis(ethylenedithio)tetrathiafulvalene monosulfones have been synthesized by the aerial oxidation of the chiral dithiolates generated from the propionitrile-protected precursors. Both enantiomers crystallize in the orthorhombic chiral space group P212121. They show a boat-type conformation of the TTF moiety, a rather rigid dithiin sulfone ring and the methyl groups in a bisequatorial conformation. Cyclic voltammetry measurements indicate fully reversible oxidation in radical cation and dication species. PMID:26199666

  12. The phase behavior of simple salt-tolerant sulfonates

    SciTech Connect

    Barakat, Y.; Fortney, L.N.; LaLanne-Cassou, C.; Schecter, R.S.; Wade, W.H.; Weerasooriya, U.; Yiv, S.

    1983-12-01

    Alkane and ..cap alpha..-olefin sulfonates can be used to produce optimal microemulsion formulations having very high salinity tolerance (including divalent ion) while maintaining large solubilization parameters and low interfacial tensions (IFT's). Such molecules require elevated temperatures or higher alcohol concentrations to suppress liquid crystal formation. As in other species, solubilization is inversely related to width of the threephase regime, and IFT and solubilization are strongly coupled.

  13. Ultrasound assisted regioselective sulfonation of aromatic compounds with sulfuric acid.

    PubMed

    Qureshi, Ziyauddin S; Deshmukh, Krishna M; Jagtap, Sachin R; Nandurkar, Nitin S; Bhanage, Bhalchandra M

    2009-03-01

    A simple and convenient methodology for selective sulfonation of aromatic compounds using sulfuric acid under sonication is described. The present methodology shows a considerable enhancement in the reaction rate along with improved selectivity compared with the reactions performed under silent conditions. The effect of various parameters such as agitation speed, sulfuric acid concentration, and temperature on reaction system have been investigated and are explained on the basis of ultrasonically generated cavitational effects. PMID:19014895

  14. Steady-state inhibition model for the biodegradation of sulfonated amines in a packed bed reactor.

    PubMed

    Juárez-Ramírez, Cleotilde; Galíndez-Mayer, Juvencio; Ruiz-Ordaz, Nora; Ramos-Monroy, Oswaldo; Santoyo-Tepole, Fortunata; Poggi-Varaldo, Héctor

    2015-05-25

    Aromatic amines are important industrial products having in their molecular structure one or more aromatic rings. These are used as precursors for the synthesis of dyes, adhesives, pesticides, rubber, fertilizers and surfactants. The aromatic amines are common constituents of industrial effluents, generated mostly by the degradation of azo dyes. Several of them are a threat to human health because they can by toxic, allergenic, mutagenic or carcinogenic. The most common are benzenesulfonic amines, such as 4-ABS (4-aminobenzene sulfonic acid) and naphthalene sulfonic amines, such as 4-ANS (4-amino naphthalene sulfonic acid). Sometimes, the mixtures of toxic compounds are more toxic or inhibitory than the individual compounds, even for microorganisms capable of degrading them. Therefore, the aim of this study was to evaluate the degradation of the mixture 4-ANS plus 4-ABS by a bacterial community immobilized in fragments of volcanic stone, using a packed bed continuous reactor. In this reactor, the amines loading rates were varied from 5.5 up to 69 mg L(-1) h(-1). The removal of the amines was determined by high-performance liquid chromatography and chemical oxygen demand. With this information, we have studied the substrate inhibition of the removal rate of the aromatic amines during the degradation of the mixture of sulfonated aromatic amines by the immobilized microorganisms. Experimental results were fitted to parabolic, hyperbolic and linear inhibition models. The model that best characterizes the inhibition of the specific degradation rate in the biofilm reactor was a parabolic model with values of RXM=58.15±7.95 mg (10(9) cells h)(-1), Ks=0.73±0.31 mg L(-1), Sm=89.14±5.43 mg L(-1) and the exponent m=5. From the microbial community obtained, six cultivable bacterial strains were isolated and identified by sequencing their 16S rDNA genes. The strains belong to the genera Variovorax, Pseudomonas, Bacillus, Arthrobacter, Nocardioides and Microbacterium. This

  15. Steady-state inhibition model for the biodegradation of sulfonated amines in a packed bed reactor.

    PubMed

    Juárez-Ramírez, Cleotilde; Galíndez-Mayer, Juvencio; Ruiz-Ordaz, Nora; Ramos-Monroy, Oswaldo; Santoyo-Tepole, Fortunata; Poggi-Varaldo, Héctor

    2015-05-25

    Aromatic amines are important industrial products having in their molecular structure one or more aromatic rings. These are used as precursors for the synthesis of dyes, adhesives, pesticides, rubber, fertilizers and surfactants. The aromatic amines are common constituents of industrial effluents, generated mostly by the degradation of azo dyes. Several of them are a threat to human health because they can by toxic, allergenic, mutagenic or carcinogenic. The most common are benzenesulfonic amines, such as 4-ABS (4-aminobenzene sulfonic acid) and naphthalene sulfonic amines, such as 4-ANS (4-amino naphthalene sulfonic acid). Sometimes, the mixtures of toxic compounds are more toxic or inhibitory than the individual compounds, even for microorganisms capable of degrading them. Therefore, the aim of this study was to evaluate the degradation of the mixture 4-ANS plus 4-ABS by a bacterial community immobilized in fragments of volcanic stone, using a packed bed continuous reactor. In this reactor, the amines loading rates were varied from 5.5 up to 69 mg L(-1) h(-1). The removal of the amines was determined by high-performance liquid chromatography and chemical oxygen demand. With this information, we have studied the substrate inhibition of the removal rate of the aromatic amines during the degradation of the mixture of sulfonated aromatic amines by the immobilized microorganisms. Experimental results were fitted to parabolic, hyperbolic and linear inhibition models. The model that best characterizes the inhibition of the specific degradation rate in the biofilm reactor was a parabolic model with values of RXM=58.15±7.95 mg (10(9) cells h)(-1), Ks=0.73±0.31 mg L(-1), Sm=89.14±5.43 mg L(-1) and the exponent m=5. From the microbial community obtained, six cultivable bacterial strains were isolated and identified by sequencing their 16S rDNA genes. The strains belong to the genera Variovorax, Pseudomonas, Bacillus, Arthrobacter, Nocardioides and Microbacterium. This

  16. Formulation of soluble oils with synthetic and petroleum sulfonates

    SciTech Connect

    Eckard, A.; Riff, I.; Weaver, J.

    1997-06-01

    Metalworking fluids for metal removal are formulated to provide cooling, lubrication, and rust protection when cutting and machining metals. There are basically four types of cutting fluids: straight oils, synthetics, semisynthetic fluids and soluble oils. The last type is the most widely used for metal removal operations such as cutting, drilling and grinding. Soluble oils used for metalworking operations are normally the oil-in-water type, with oil as the internal phase and water as the external phase. The soluble oils can have rather complex compositions, usually containing two or more emulsifiers and coupling agents, as well as additives to provide rust inhibition, lubricity, detergency, resistance to bacterial attack and foam control. The dominant emulsifier in a soluble oil is usually sodium sulfonate which also has the secondary benefit of being a rust inhibitor. Soluble oil emulsions based on petroleum or synthetic sulfonates have been found to improve lubrication and cleaning of metal parts and equipment. As has been done previously, a series of emulsification studies were conducted using petroleum and synthetic sulfonates. Emulsifier level, coemulsifiers and minor formulation adjustments were made to optimize each system. This study was made using naphthenic oil basestock. Formulations were evaluated using criteria including concentrate stability, hard and soft water emulsion stability, emulsibility, foaming tendency and response to defoamers, antirust properties and cost effectiveness of individual formulations. The results of these evaluations are presented in the present paper.

  17. Synthesis of 3-O-sulfonated heparan sulfate octasaccharides that inhibit the herpes simplex virus type 1 host-cell interaction

    NASA Astrophysics Data System (ADS)

    Hu, Yu-Peng; Lin, Shu-Yi; Huang, Cheng-Yen; Zulueta, Medel Manuel L.; Liu, Jing-Yuan; Chang, Wen; Hung, Shang-Cheng

    2011-07-01

    Cell surface carbohydrates play significant roles in a number of biologically important processes. Heparan sulfate, for instance, is a ubiquitously distributed polysulfated polysaccharide that is involved, among other things, in the initial step of herpes simplex virus type 1 (HSV-1) infection. The virus interacts with cell-surface heparan sulfate to facilitate host-cell attachment and entry. 3-O-Sulfonated heparan sulfate has been found to function as an HSV-1 entry receptor. Achieving a complete understanding of these interactions requires the chemical synthesis of such oligosaccharides, but this remains challenging. Here, we present a convenient approach for the synthesis of two irregular 3-O-sulfonated heparan sulfate octasaccharides, making use of a key disaccharide intermediate to acquire different building blocks for the oligosaccharide chain assembly. Despite substantial structural differences, the prepared 3-O-sulfonated sugars blocked viral infection in a dosage-dependent manner with remarkable similarity to one another.

  18. Preparation and Characterization of Sulfonic Acid Functionalized Silica and Its Application for the Esterification of Ethanol and Maleic Acid

    NASA Astrophysics Data System (ADS)

    Sirsam, Rajkumar; Usmani, Ghayas

    2016-04-01

    The surface of commercially available silica gel, 60-200 mesh size, was modified with sulfonic acid through surface activation, grafting of 3-Mercaptopropyltrimethoxysilane, oxidation and acidification of 3-Mercaptopropylsilica. Sulfonic Acid Functionalization of Silica (SAFS) was confirmed by Fourier Transform Infra-red (FTIR) spectroscopy and thermal gravimetric analysis. Acid-base titration was used to estimate the cation exchange capacity of the SAFS. Catalytic activity of SAFS was judged for the esterification of ethanol with maleic acid. An effect of different process parameters viz. molar ratio, catalyst loading, speed of agitation and temperature were studied and optimized by Box Behnken Design (BBD) of Response Surface Methodology (RSM). Quadratic model developed by BBD-RSM reasonably satisfied an experimental and predicted values with correlation coefficient value R2 = 0.9504.

  19. Proton Conduction in Sulfonated Organic-Inorganic Hybrid Monoliths with Hierarchical Pore Structure.

    PubMed

    von der Lehr, Martin; Seidler, Christopher F; Taffa, Dereje H; Wark, Michael; Smarsly, Bernd M; Marschall, Roland

    2016-09-28

    Porous organic-inorganic hybrid monoliths with hierarchical porosity exhibiting macro- and mesopores are prepared via sol-gel process under variation of the mesopore size. Organic moieties in the pore walls are incorporated by substituting up to 10% of the silicon precursor tetramethylorthosilicate with bisilylated benzene molecules. After functionalization with sulfonic acid groups, the resulting sulfonated hybrid monoliths featuring a bimodal pore structure are investigated regarding proton conduction depending on temperature and relative humidity. The hierarchical pore system and controlled mesopore design turn out to be crucial for sulfonation and proton conduction. These sulfonated hybrid hierarchical monoliths containing only 10% organic precursor exhibit higher proton conduction at different relative humidities than sulfonated periodic mesoporous organosilica made of 100% bisilylated precursors exhibiting solely mesopores, even with a lower concentration of sulfonic acid groups. PMID:27598017

  20. Proton Conduction in Sulfonated Organic-Inorganic Hybrid Monoliths with Hierarchical Pore Structure.

    PubMed

    von der Lehr, Martin; Seidler, Christopher F; Taffa, Dereje H; Wark, Michael; Smarsly, Bernd M; Marschall, Roland

    2016-09-28

    Porous organic-inorganic hybrid monoliths with hierarchical porosity exhibiting macro- and mesopores are prepared via sol-gel process under variation of the mesopore size. Organic moieties in the pore walls are incorporated by substituting up to 10% of the silicon precursor tetramethylorthosilicate with bisilylated benzene molecules. After functionalization with sulfonic acid groups, the resulting sulfonated hybrid monoliths featuring a bimodal pore structure are investigated regarding proton conduction depending on temperature and relative humidity. The hierarchical pore system and controlled mesopore design turn out to be crucial for sulfonation and proton conduction. These sulfonated hybrid hierarchical monoliths containing only 10% organic precursor exhibit higher proton conduction at different relative humidities than sulfonated periodic mesoporous organosilica made of 100% bisilylated precursors exhibiting solely mesopores, even with a lower concentration of sulfonic acid groups.

  1. Poly(ether sulfone) as a negative resist for electron beam lithography

    NASA Astrophysics Data System (ADS)

    Bryce, R. M.; Freeman, M. R.; Aktary, M.

    2007-05-01

    The sulfone containing polymer poly(butene sulfone) has long been used as positive electron beam resist due to the high scission rate of sulfone under electron irradiation. The authors demonstrate that poly(ether sulfone) acts as a high resolution negative electron beam resist which displays good chemical and dry-etch resistance. The electron beam exposure sensitivity at 10kV was found to be approximately 230μC/cm2 for poly(ether sulfone), roughly 2.3 times that of poly(methyl methacrylate). As poly(ether sulfone) is a robust engineering polymer that can withstand etching this polymer is a suitable mask material and has properties of interest for direct incorporation in devices.

  2. Calcium carbonate phase transformations during the carbonation reaction of calcium heavy alkylbenzene sulfonate overbased nanodetergents preparation.

    PubMed

    Chen, Zhaocong; Xiao, Shan; Chen, Feng; Chen, Dongzhong; Fang, Jianglin; Zhao, Min

    2011-07-01

    The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO(3) serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)(2) prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications.

  3. Syntheses of biodiesel precursors: sulfonic acid catalysts for condensation of biomass-derived platform molecules.

    PubMed

    Balakrishnan, Madhesan; Sacia, Eric R; Bell, Alexis T

    2014-04-01

    Synthesis of transportation fuel from lignocellulosic biomass is an attractive solution to the green alternative-energy problem. The production of biodiesel, in particular, involves the process of upgrading biomass-derived small molecules to diesel precursors containing a specific carbon range (C11 -C23). Herein, a carbon-upgrading process utilizing an acid-catalyzed condensation of furanic platform molecules from biomass is described. Various types of sulfonic acid catalysts have been evaluated for this process, including biphasic and solid supported catalysts. A silica-bound alkyl sulfonic acid catalyst has been developed for promoting carbon-carbon bond formation of biomass-derived carbonyl compounds with 2-methylfuran. This hydrophobic solid acid catalyst exhibits activity and selectivity that are comparable to those of a soluble acid catalyst. The catalyst can be readily recovered and recycled, possesses appreciable hydrolytic stability in the presence of water, and retains its acidity over multiple reaction cycles. Application of this catalyst to biomass-derived platform molecules led to the synthesis of a variety of furanic compounds, which are potential biodiesel precursors.

  4. Preparation of sulfonic acid-containing rubbers from natural rubber vulcanizates

    NASA Astrophysics Data System (ADS)

    Poonsawat, Worapong; Poompradub, Sirilux; Ngamcharussrivichai, Chawalit

    2014-06-01

    In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H2O2) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H2O2: HCOOH = 1:1, the concentration of H2O2 = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

  5. Conversion of Dexon (p-Dimethylaminobenzenediazo Sodium Sulfonate) to N,N-Dimethyl-p-Phenylenediamine by Pseudomonas fragi Bk9

    PubMed Central

    Karanth, N. G. K.; Bhat, S. G.; Vaidyanathan, C. S.; Vasantharajan, V. N.

    1974-01-01

    The metabolism of the fungicide Dexon (p-dimethylaminobenzenediazo sodium sulfonate) by a soil bacterium is reported for the first time. The organism which is capable of using Dexon only by a co-metabolic process was obtained by enrichment culture and was identified as Pseudomonas fragi. The first metabolic product of Dexon was identified as N,N-dimethyl-p-phenylenediamine. The presence of an enzyme, p-dimethylaminobenzenediazo sodium sulfonate reductase, capable of reducing Dexon to N,N-dimethyl-p-phenylenediamine has been demonstrated in the cell-free extracts of the organism. The enzyme is found to be in the soluble fraction and requires dithiothreitol as a reductant. PMID:4809909

  6. Sulfonates: A novel class of organic sulfur compounds in marine sediments

    NASA Astrophysics Data System (ADS)

    Vairavamurthy, Appathurai; Zhou, Weiqing; Eglinton, Timothy; Manowitz, Bernard

    1994-11-01

    X-ray absorption near-edge structure spectroscopy (XANES) used to measure sulfur speciation in a variety of organic-rich marine sediments has established sulfonates as a novel and major component of sedimentary organic sulfur. The origins of sulfonates in sediments are not clear, although both biological and geochemical mechanisms are possible. The accumulation of oxidized sulfonate sulfur in reducing marine sediments was not known previously; hence, a new perspective in sulfur geochemistry is established. The biogeochemical implications of the presence of sulfonates in marine sediments are discussed.

  7. Pendant dual sulfonated poly(arylene ether ketone) proton exchange membranes for fuel cell application

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh Dat Thinh; Yang, Sungwoo; Kim, Dukjoon

    2016-10-01

    Poly(arylene ether ketone) (PAEK) possessing carboxylic groups at the pendant position is synthesized, and the substitution degree of pendant carboxylic groups is controlled by adjusting the ratio of 4,4-bis(4-hydroxyphenyl)valeric acid and 2,2-bis(4-hydroxyphenyl)propane. Dual sulfonated 3,3-diphenylpropylamine (SDPA) is grafted onto PAEK as a proton-conducting moiety via the amidation reaction with carboxylic groups. The transparent and flexible membranes with different degrees of sulfonation are fabricated so that we can test and compare their structure and properties with a commercial Nafion® 115 membrane for PEMFC applications. All prepared PAEK-SDPA membranes exhibit good oxidative and hydrolytic stability from Fenton's and high temperature water immersion test. SAXS analysis illustrates an excellent phase separation between the hydrophobic backbone and hydrophilic pendant groups, resulting in big ionic clusters. The proton conductivity was measured at different relative humidity, and its behavior was analyzed by hydration number of the membrane. Among a series of membranes, some samples (including B20V80-SDPA) show not only higher proton conductivity, but also higher integrated cell performance than those of Nafion® 115 at 100% relative humidity, and thus we expect these to be good candidate membranes for proton exchange membrane fuel cells (PEMFCs).

  8. Bioseparation of papain from Carica papaya latex by precipitation of papain-poly (vinyl sulfonate) complexes.

    PubMed

    Braia, Mauricio; Ferrero, Maximiliano; Rocha, María Victoria; Loureiro, Dana; Tubio, Gisela; Romanini, Diana

    2013-09-01

    The formation of insoluble complexes between enzymes and polyelectrolytes is a suitable technique for isolating these biomolecules from natural sources, because it is a simple and rapid technique that allows the concentration of the protein. This technique can be used in most purification protocols at the beginning of the downstream process. The aim of this investigation is to isolate papain from Carica papaya latex by precipitation of insoluble complexes between this enzyme and poly (vinyl sulfonate). The papain-poly (vinyl sulfonate) complex was insoluble at pH lower than 6, with a PVS/PAP stoichiometric ratio of 1:279. Ionic strength affected the complex formation. The presence of the polymer increased the enzymatic activity and protected the enzyme from autodegradation. The optimal conditions for the formation of insoluble papain-polyelectrolyte complex formation were applied to C. papaya latex and a high recovery was obtained (around 86%) and a purification factor around 2. This method can be applied as an isolation method of papain from C. papaya latex or as a first step in a larger purification strategy.

  9. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    PubMed

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature.

  10. Metastable atom-activated dissociation mass spectrometry of phosphorylated and sulfonated peptides in negative ion mode.

    PubMed

    Cook, Shannon L; Jackson, Glen P

    2011-06-01

    The dissociation behavior of phosphorylated and sulfonated peptide anions was explored using metastable atom-activated dissociation mass spectrometry (MAD-MS) and collision-induced dissociation (CID). A beam of high kinetic energy helium (He) metastable atoms was exposed to isolated phosphorylated and sulfonated peptides in the 3- and 2- charge states. Unlike CID, where phosphate losses are dominant, the major dissociation channels observed using MAD were C(α) - C peptide backbone cleavages and neutral losses of CO(2), H(2)O, and [CO(2) + H(2)O] from the charge reduced (oxidized) product ion, consistent with an electron detachment dissociation (EDD) mechanism such as Penning ionization. Regardless of charge state or modification, MAD provides ample backbone cleavages with little modification loss, which allows for unambiguous PTM site determination. The relative abundance of certain fragment ions in MAD is also demonstrated to be somewhat sensitive to the number and location of deprotonation sites, with backbone cleavage somewhat favored adjacent to deprotonated sites like aspartic acid residues. MAD provides a complementary dissociation technique to CID, ECD, ETD, and EDD for peptide sequencing and modification identification. MAD offers the unique ability to analyze highly acidic peptides that contain few to no basic amino acids in either negative or positive ion mode.

  11. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    DOE PAGES

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformedmore » a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.« less

  12. The Alkaline Hydrolysis of Sulfonate Esters: Challenges in Interpreting Experimental and Theoretical Data

    PubMed Central

    2013-01-01

    Sulfonate ester hydrolysis has been the subject of recent debate, with experimental evidence interpreted in terms of both stepwise and concerted mechanisms. In particular, a recent study of the alkaline hydrolysis of a series of benzene arylsulfonates (Babtie et al., Org. Biomol. Chem.10, 2012, 8095) presented a nonlinear Brønsted plot, which was explained in terms of a change from a stepwise mechanism involving a pentavalent intermediate for poorer leaving groups to a fully concerted mechanism for good leaving groups and supported by a theoretical study. In the present work, we have performed a detailed computational study of the hydrolysis of these compounds and find no computational evidence for a thermodynamically stable intermediate for any of these compounds. Additionally, we have extended the experimental data to include pyridine-3-yl benzene sulfonate and its N-oxide and N-methylpyridinium derivatives. Inclusion of these compounds converts the Brønsted plot to a moderately scattered but linear correlation and gives a very good Hammett correlation. These data suggest a concerted pathway for this reaction that proceeds via an early transition state with little bond cleavage to the leaving group, highlighting the care that needs to be taken with the interpretation of experimental and especially theoretical data. PMID:24279349

  13. Synthesis, characterization, antibacterial activity and quantum chemical studies of N'-Acetyl propane sulfonic acid hydrazide

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Alyar, Hamit; Ozdemir, Ummuhan Ozmen; Sahin, Omer; Kaya, Kerem; Ozbek, Neslihan; Gunduzalp, Ayla Balaban

    2015-08-01

    A new N'-Acetyl propane sulfonic acid hydrazide, C3H7sbnd SO2sbnd NHsbnd NHsbnd COCH3 (Apsh, an sulfon amide compound) has been synthesized for the first time. The structure of Apsh was investigated using elemental analysis, spectral (IR, 1H/13C NMR) measurements. In addition, molecular structure of the Apsh was determined by single crystal X-ray diffraction technique and found that the compound crystallizes in monoclinic, space group P 21/c. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The structure of Apsh is optimized using Density Functional Theory (DFT) method. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The theoretical IR frequencies are found to be in good agreement with the experimental IR frequencies. Nonlinear optical (NLO) behaviour of Apsh is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The antibacterial activities of synthesized compound were studied against Gram positive bacteria: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 23212, Staphylococcus epidermidis ATCC 34384, Gram negative bacteria: Eschericha coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70063 by using microdilution method (as MICs) and disc diffusion method.

  14. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    SciTech Connect

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  15. Electroactive nanostructured polymer actuators fabricated using sulfonated styrenic pentablock copolymer/montmorillonite/ionic liquid nanocomposite membranes

    NASA Astrophysics Data System (ADS)

    Lee, Jang-Woo; Hong, Soon Man; Koo, Chong Min

    2014-08-01

    High-bendable, air-operable ionic polymer-metal composite (IPMC) actuators composed of electroactive nanostructured middle-block sulfonated styrenic pentablock copolymer (SSPB)/sulfonated montmorillonite (s-MMT) nanocomposite electrolyte membranes with bulky imidazolium ionic liquids (ILs) incorporated were fabricated and their bending actuation performances were evaluated. The SSPB-based IPMC actuators showed larger air-operable bending displacements, higher displacement rates, and higher energy efficiency of actuations without conventional IPMC bottlenecks, including back relaxation and actuation instability during actuation in air, than the Nafion counterpart. Incorporation of s-MMT into the SSPB matrix further enhanced the actuation performance of the IPMC actuators in terms of displacement, displacement rate, and energy efficiency. The remarkably high performance of the SSPB/s-MMT/IL IPMCs was considered to be due to the microphase-separated large ionic domains of the SSPB (the average diameter of the ionic domain: ca. 20 nm) and the role of s-MMT as an ionic bridge between the ionic domains, and the ion pumping effect of the bulky imidazolium cations of the ILs as well. The microphase-separated nanostructure of the composite membranes caused a high dimensional stability upon swelling in the presence of ILs, which effectively preserved the original electrode resistance against swelling, leading to a high actuation performance of IPMC.

  16. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    SciTech Connect

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformed a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.

  17. Effect of a sulfonated azo dye and sulfanilic acid on nitrogen transformation processes in soil.

    PubMed

    Topaç, F Olcay; Dindar, Efsun; Uçaroğlu, Selnur; Başkaya, Hüseyin S

    2009-10-30

    Introduction of organic dyes into soil via wastewater and sludge applications has been of increasing concern especially in developing or under-developed countries where appropriate management strategies are scarce. Assessing the response of terrestrial ecosystems to organic dyes and estimating the inhibition concentrations will probably contribute to soil remediation studies in regions affected by the same problem. Hence, an incubation study was conducted in order to investigate the impact of a sulfonated azo dye, Reactive Black 5 (RB5) and sulfanilic acid (SA), a typical representative of aromatic sulfonated amines, on soil nitrogen transformation processes. The results apparently showed that nitrogen related processes in soil can be used as bioindicators of anthropogenic stress caused by organic dyes. It was found that urease activity, arginine ammonification rate, nitrification potential and ammonium oxidising bacteria numbers decreased by 10-20% and 7-28% in the presence of RB5 (> 20 mg/kg dry soil) and SA (> 8 mg/kg dry soil), respectively. Accordingly, it was concluded that organic dye pollution may restrict the nitrogen-use-efficiency of plants, thus further reducing the productivity of terrestrial ecosystems. Furthermore, the response of soil microbiota to SA suggested that inhibition effects of the organic dye may continue after the possible reduction of the parent dye to associated aromatic amines.

  18. Determination of methiocarb and its degradation products, methiocarb sulfoxide and methiocarb sulfone, in bananas using QuEChERS extraction.

    PubMed

    Plácido, Alexandra; Paíga, Paula; Lopes, David H; Correia, Manuela; Delerue-Matos, Cristina

    2013-01-16

    The present work describes the development of an analytical method for the determination of methiocarb and its degradation products (methiocarb sulfoxide and methiocarb sulfone) in banana samples, using the QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure followed by liquid chromatography coupled to photodiode array detector (LC-PAD). Calibration curves were linear in the range of 0.5-10 mg L⁻¹ for all compounds studied. The average recoveries, measured at 0.1 mg kg⁻¹ wet weight, were 92.0 (RSD = 1.8%, n = 3), 84.0 (RSD = 3.9%, n = 3), and 95.2% (RSD = 1.9%, n = 3) for methiocarb sulfoxide, methiocarb sulfone, and methiocarb, respectively. Banana samples treated with methiocarb were collected from an experimental field. The developed method was applied to the analysis of 24 samples (peel and pulp) and to 5 banana pulp samples. Generally, the highest levels were found for methiocarb sulfoxide and methiocarb. Methiocarb sulfone levels were below the limit of quantification, except in one sample (not detected).

  19. Interactions of formate ion with triplets of anthraquinone-2-sulfonate, 1,4-naphthoquinone, benzophenone-4-carboxylate, and benzophenone-4-sulfonate

    SciTech Connect

    Loeff, I.; Goldstein, S.; Treinin, A. ); Linschitz, H. )

    1991-05-30

    The interaction of formate with the triplet states of naphthoquinone (NQ), anthraquinone-2-sulfonate (AQS), benzophenone-4-carboxylate (BC), and benzophenone-4-sulfonate (BS) was studied by laser flash photolysis. Rate constants were determined either by direct measurement of triplet lifetimes or by inhibition of product yields by competitive reactants. Radical products are formed in two stages, direct reduction by formate and efficient secondary reduction by initially formed CO{sub 2}{sup {sm bullet}{minus}} radicals. The quinones react by electron transfer with quenching rate constants k{sub q}(NQ) = 3 {times} 10{sup 9} and k{sub q}(AQS) = 4 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}, giving anion radicals with primary yields of {phi}{sub R}(NQ) {approximately} 0.7 and {phi}{sub R}(AQS) {approximately} 0.3. Formic acid quenches {sup 3}AQS much more slowly. The less strongly oxidizing ketone triplets react by H-atom abstraction, k{sub q}(BC) = 1.3 {times} 10{sup 7} and k{sub q}(BS) = 5.3 {times} 10{sup 7} M{sup {minus}1} s{sup {minus}1}, giving protonated ketyl radicals with primary yields {phi}{sub R} {approximately} 0.7. Photoreduction of BC exhibits a deuterium isotope effect, k{sub H}/k{sub D} = 1.6, whereas AQS shows none. A new, short-lived transient, E, is observed in the {sup 3}AQS-formate reaction, which may be an exciplex or adduct. The redox potential, E{degree}{prime}(NQ/NQ{sup {sm bullet}{minus}}) = {minus}0.12 V, and rate constants for radical reactions of NQ and O{sub 2} were measured by pulse radiolysis. The results are discussed in terms of pertinent redox potentials, bond strengths, and the nature of the exciplex intermediates.

  20. Study of sodium tanshinone II A sulfonate tissue distribution in rat by liquid chromatography/tandem mass spectrometry.

    PubMed

    He, Tingting; Zou, Qiaogen; Feng, Zhenbin; Zhang, Zunjian

    2010-01-01

    A rapid and sensitive method based on liquid chromatography/tandem mass spectrometry (LC-MS/MS) has been developed and fully validated for the quantitative determination of sodium tanshinone IIA sulfonate (STS, sodium (1,6,6-trimethyl-10,11-dioxo-7,8,9-trihydrophenanthro[1,2-b]furan)-yl-2-sulfonate) in rat biosamples including plasma and different tissues using sodium tanshinone I sulfonate (sodium (1,6-dimethyl-10,11-dioxo-phenanthro[1,2-b]furan)-yl-2-sulfonate) as internal standard. Simple protein precipitation by acetonitrile was utilized for extracting STS from the rat biosamples. Chromatographic separation of the sample matrix from the analyte and the internal standard was performed using a commercially available analytical column with a mobile phase consisting of methanol-5 mmoL/L ammonia acetate (70:30, v/v) at a flow rate of 0.2 mL/min. Detection was performed on a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization source and operated in the negative-ion mode. The intra- and inter-day precisions (RSD%) and deviations of the assay accuracies were within 10.0% for STS. The extraction recovery of STS was more than 86.5%. The limit of detection (LOD) of STS was 1.0 ng/mL. The method was successfully applied to the tissue distribution study of STS intravenously administered to healthy Sprague-Dawley rats. The tissue distribution results showed that liver, kidney, lung, small intestine and duodenum were the major distribution tissues of STS in rats, and that STS had difficulty in crossing the blood-brain barrier. After 24 h, STS could be detected only in the kidney, stomach and small intestine, indicating that there was no long-term accumulation of STS in rat. PMID:21175038

  1. Synthesis and solid-state NMR characterization of cubic mesoporous silica SBA-1 functionalized with sulfonic acid groups.

    PubMed

    Tsai, Hui-Hsu Gavin; Chiu, Po-Jui; Jheng, Guang-Liang; Ting, Chun-Chiang; Pan, Yu-Chi; Kao, Hsien-Ming

    2011-07-01

    Well-ordered cubic mesoporous silicas SBA-1 functionalized with sulfonic acid groups have been synthesized through in situ oxidation of mercaptopropyl groups with H(2)O(2) via co-condensation of tetraethoxysilane (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) templated by cetyltriethylammonium bromide (CTEABr) under strong acidic conditions. Various synthesis parameters such as the amounts of H(2)O(2) and MPTMS on the structural ordering of the resultant materials were systematically investigated. The materials thus obtained were characterized by a variety of techniques including powder X-ray diffraction (XRD), multinuclear solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, (29)Si{(1)H} 2D HETCOR (heteronuclear correlation) NMR spectroscopy, thermogravimetric analysis (TGA), and nitrogen sorption measurements. By using (13)C CPMAS NMR technique, the status of the incorporated thiol groups and their transformation to sulfonic acid groups can be monitored and, as an extension, to define the optimum conditions to be used for the oxidation reaction to be quantitative. In particular, (29)Si{(1)H} 2D HETCOR NMR revealed that the protons in sulfonic acid groups are in close proximity to the silanol Q(3) species, but not close enough to form a hydrogen bond.

  2. Methylation, Glucuronidation, and Sulfonation of Daphnetin in Human Hepatic Preparations In Vitro: Metabolic Profiling, Pathway Comparison, and Bioactivity Analysis.

    PubMed

    Liang, Si-Cheng; Xia, Yang-Liu; Hou, Jie; Ge, Guang-Bo; Zhang, Jiang-Wei; He, Yu-Qi; Wang, Jia-Yue; Qi, Xiao-Yi; Yang, Ling

    2016-02-01

    Our previous study demonstrated that daphnetin is subject to glucuronidation in vitro. However, daphnetin metabolism is still poorly documented. This study aimed to investigate daphnetin metabolism and its consequent effect on the bioactivity. Metabolic profiles obtained by human liver S9 fractions and human hepatocytes showed that daphnetin was metabolized by glucuronidation, sulfonation, and methylation to form 6 conjugates which were synthesized and identified as 7-O-glucuronide, 8-O-glucuronide, 7-O-sulfate and 8-O-sulfate, 8-O-methylate, and 7-O-suflo-8-O-methylate. Regioselective 8-O-methylation of daphnetin was investigated using in silico docking calculations, and the results suggested that a close proximity (2.03 Å) of 8-OH to the critical residue Lysine 144 might be the responsible mechanism. Compared with glucuronidation and sulfonation pathways, the methylation of daphnetin had a high clearance rate (470 μL/min/mg) in human liver S9 fractions and contributed to a large amount (37.3%) of the methyl-derived metabolites in human hepatocyte. Reaction phenotyping studies showed the major role of SULT1A1, -1A2, and -1A3 in daphnetin sulfonation, and soluble COMT in daphnetin 8-O-methylation. Of the metabolites, only 8-O-methyldaphnetin exhibited an inhibitory activity on lymphocyte proliferation comparable to that of daphnetin. In conclusion, methylation is a crucial pathway for daphnetin clearance and might be involved in pharmacologic actions of daphnetin in humans. PMID:26869431

  3. Hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (PIEEK) for fuel cell membranes

    NASA Astrophysics Data System (ADS)

    Chang, Guanjun; Shang, Zhenfang; Yang, Li

    2015-05-01

    A new diamine monomer, 3,3‧-dihydroxydiphenylamine, is prepared by the palladium catalyzed C-N coupling reaction and the following reduction reaction of 3-bromoanisole and m-anisidine. A series of novel hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (SPIEEK) are obtained by the copolymerization of sodium 5,5‧-carbonylbis(2-fluorobenzene sulfonate), 4,4‧-difluorobenzophenone with 3,3‧-dihydroxydiphenylamine. The structures of resulting polymers are characterized by means of FT-IR, 1H NMR spectroscopy, and elemental analysis; the results show an agreement with the proposed structure. The resulting SPIEEK membranes display much better resistance to swelling than these without imino groups due to the strong interchain interaction through imino and sulfonic acid groups. The SPIEEK-60 and SPIEEK-80 membrane show the proton conductivity of 0.118 and 0.154 S cm-1 at 80 °C which is higher than Nafion 117 (0.082 S cm-1 at 80 °C). Moreover, the SPIEEK membranes exhibit good mechanical properties and lower methanol permeability due to the hydrogen bondings between the polymer chains.

  4. Sulfone/Ester Polymers Containing Pendent Ethynyl Groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.; Jensen, B. J.

    1986-01-01

    Two processes make high-performance polymers resistant to solvents, without compromising mechanical characteristics. Polymers show improved solvent resistance while retaining high toughness, thermoformability, and mechanical performance. Multistep process involves conversion of pendent bromo group to ethynyl group, while direct process involves reacting hydroxy-terminated sulfone oligomers or polymers with stoichiometric amount of 5-(4-ethynylphenoxy) isophthaloyl chloride. Applications for new polymers include adhesives, composite resin matrices, moldings, ultrafiltration membranes, protective coatings, and such electrical insulators as thin films for microelectronic circuitry.

  5. Photo- and Electroluminescence of Substituted Divinyl Dibenzothiophene Sulfone

    NASA Astrophysics Data System (ADS)

    Samsonova, L. G.; Degtyarenko, K. M.; Kopylova, T. N.; Palatova, A. V.; Kukhta, A. V.

    2016-08-01

    The spectral properties of two substituted divinyl dibenzothiophene sulfone in solutions of tetrahydrofuran, polyvinylcarbazole films, and films obtained by thermal vacuum deposition are investigated. The ability of these compounds in thin-layer ITO/PEDOT:PSS/NPD/L/Ca/Al and ITO/PEDOT:PSS/PVK+L/Ca/Al structures (L denotes the examined luminophore) to emit radiation at applied voltage is investigated. It is shown that the spectra of photo- and electroluminescence in the film have a strong red shift of ~100 nm compared to the photoluminescence in solutions. It is suggested that radiation belongs to excimers.

  6. The Palladium-Catalyzed Trifluoromethylation of Vinyl Sulfonates

    PubMed Central

    Cho, Eun Jin; Buchwald, Stephen L.

    2011-01-01

    A method for the palladium-catalyzed trifluoromethylation of cyclohexenyl sulfonates has been developed. Various cyclohexenyl triflates and nonaflates underwent trifluoromethylation under mild reaction conditions using a catalyst system composed of Pd(dba)2 or [(allyl)PdCl]2 and the monodentate biaryl phosphine ligand tBuXPhos. The trifluoromethyl anion (CF3−) or its equivalent for the process was generated in situ from TMSCF3 in combination with KF or TESCF3 in combintion with RbF. PMID:22111687

  7. Bis(3-amino-phen-yl) sulfone acetonitrile solvate.

    PubMed

    Yao, Wei; Li, Fang-Shi; Yu, Da-Sheng; Lu, Chui; Zhu, Jin-Na

    2008-05-21

    In the sulfone mol-ecule of the title compound, C(12)H(12)N(2)O(2)S·C(2)H(3)N, the two benzene rings are oriented at a dihedral angle of 80.69 (3)°. Weak intra-molecular C-H⋯O hydrogen bonds result in the formation of two five-membered rings, which both have envelope conformations. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules.

  8. Rh(III)-catalyzed synthesis of sultones through C-H activation directed by a sulfonic acid group.

    PubMed

    Qi, Zisong; Wang, Mei; Li, Xingwei

    2014-09-01

    A new rhodium-catalyzed synthesis of sultones via the oxidative coupling of sulfonic acids with internal alkynes is described. The reaction proceeds via aryl C-H activation assisted by a sulfonic acid group.

  9. Arylative Desulfonation of Diarylmethyl Phenyl Sulfone with Arenes Catalyzed by Scandium Triflate.

    PubMed

    Nambo, Masakazu; Ariki, Zachary T; Canseco-Gonzalez, Daniel; Beattie, D Dawson; Crudden, Cathleen M

    2016-05-20

    A scandium-triflate-catalyzed arylative desulfonation of diarylmethyl phenyl sulfones with arenes and heteroarenes was established. A variety of both sulfone and arene substrates were reacted to afford symmetric and nonsymmetric triarylmethanes in good yields. Further transformations of the resulting triarylmethanes and application to the concise synthesis of a bactericidal agent analogue were also demonstrated.

  10. Arylative Desulfonation of Diarylmethyl Phenyl Sulfone with Arenes Catalyzed by Scandium Triflate.

    PubMed

    Nambo, Masakazu; Ariki, Zachary T; Canseco-Gonzalez, Daniel; Beattie, D Dawson; Crudden, Cathleen M

    2016-05-20

    A scandium-triflate-catalyzed arylative desulfonation of diarylmethyl phenyl sulfones with arenes and heteroarenes was established. A variety of both sulfone and arene substrates were reacted to afford symmetric and nonsymmetric triarylmethanes in good yields. Further transformations of the resulting triarylmethanes and application to the concise synthesis of a bactericidal agent analogue were also demonstrated. PMID:27124389

  11. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  12. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  13. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  14. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  15. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  16. Bis-sulfonic acid ionic liquids for the conversion of fructose to 5-hydroxymethyl-2-furfural.

    PubMed

    Sim, Sang Eun; Kwon, Sunjeong; Koo, Sangho

    2012-10-31

    Homogenous bis-sulfonic acid ionic liquids (1 mol equiv.) in DMSO (10 mol equiv.) at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids.

  17. Synthesis and Structure-Property Relationships of Poly(sulfone)s for Anion Exchange Membranes

    SciTech Connect

    Yan, JL; Moore, HD; Hibbs, MR; Hickner, MA

    2013-10-05

    Membranes based on cationic polymers that conduct anions are important for enabling alkaline membrane fuel cells and other solid-state electrochemical devices that operate at high pH. Anion exchange membranes with poly(arylene ether sulfone) backbones are demonstrated by two routes: chloromethylation of commercially available poly(sulfone)s or radical bromination of benzylmethyl moieties in poly(sulfone)s containing tetramethylbisphenol A monomer residues. Polymers with tethered trimethylbenzyl ammonium moieties resulted from conversion of the halomethyl groups by quaternization with trimethyl amine. The water uptake of the chloromethylated polymers was dependent on the type of poly(sulfone) backbone for a given IEC. Bisphenol A-based Udel (R) poly(sulfone) membranes swelled in water to a large extent while membranes from biphenol-based Radel (R) poly(sulfone), a stiffer backbone than Udel, only showed moderate water uptake. The water uptake of cationic poly(sulfone)s was further reduced by synthesizing tetramethylbisphenol A and 4,4-biphenol-containing poly(sulfone) copolymers where the ionic groups were clustered on the tetramethylbisphenol A residues. The conductivity of all samples scaled with the bulk water uptake. The hydration number of the membranes could be increased by casting membranes from the ionic form polymers versus converting the halomethyl form cast polymers to ionic form in the solid state. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1790-1798, 2013

  18. Solvation Behavior of Short-chain Polystyrene Sulfonate in Aqueous Electrolyte Solutions: A Molecular Dyamics Study

    SciTech Connect

    Chialvo, Ariel A; Simonson, J Michael {Mike}

    2005-01-01

    We analyze the solvation behavior of short-chain polystyrene sulfonate (PSS) in aqueous electrolyte solutions by isothernal-isochoric molecular dynamics simulation to determine the solvation effects on the structure and conformation of the polyelectrolyte as a function of the aqueous environment. To that end, we study these aqueous systems including the explicit atomistic description of water, the PSS chain, and their interactions with all species in solution. In addition, we investigate the effect of the degree of sulfonation and its distribution along the PSS chain on the resulting conformation as well as solvation structure. Moreover, we assess the impact of added salts on the net charge of the PSS backbone, placing emphasis on the valence of the counterion and the extent of the ion-pair formation between the sulfonate group and the counterions. Finally, we present evidence for the so-called like-charge attraction between sulfonate groups through the formation of counterion-mediated interchain sulfonate-sulfonate and water-mediated intrachain sulfonate-sulfonate bridges, as well as between unlike counterion-counterion interactions.

  19. Enantioselective transformation of Na2SO3 into allylic sulfonic acids under Pd catalysis.

    PubMed

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang

    2015-01-14

    Pd-catalyzed asymmetric allylic sulfonation of di-aryl-substituted allylic acetates with sodium sulfite (Na2SO3) in THF-H2O at room temperature was described. This method directly provided allylic sulfonic acids in up to excellent yield and enantioselectivity. PMID:25415622

  20. Colonic necrosis due to calcium polystyrene sulfonate (Kalimate) not suspended in sorbitol.

    PubMed

    Castillo-Cejas, María Dolores; de-Torres-Ramírez, Inés; Alonso-Cotoner, Carmen

    2013-04-01

    Cation-exchange resins are used in the management of hyperkalemia, particularly in patients with end-stage renal disease. These resins were associated with gastrointestinal tract lesions, especially sodium polystyrene sulfonate (Kayexalate) mixed with sorbitol. We present a case of colonic necrosis after the administration of calcium polystyrene sulfonate (Kalimate) not suspended in sorbitol.

  1. Calix[4]arene sulfonate as a template for forming fluorescent thiazole orange H-aggregates.

    PubMed

    Lau, Vivian; Heyne, Belinda

    2010-05-28

    The unexpected interaction between thiazole orange (TO) and calix[4]arene sulfonate is reported herein. H-Aggregates of TO switching on their fluorescence in solution are observed. Surprisingly, fluorescence enhancement is not linked to host-guest inclusion, but rather to calix[4]arene sulfonate serving as a template for several TO molecules.

  2. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... salts (generic). 721.10487 Section 721.10487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  3. Aryl sulfonates as neutral photoacid generators (PAGs) for EUV lithography

    NASA Astrophysics Data System (ADS)

    Sulc, Robert; Blackwell, James M.; Younkin, Todd R.; Putna, E. Steve; Esswein, Katherine; DiPasquale, Antonio G.; Callahan, Ryan; Tsubaki, Hideaki; Tsuchihashi, Tooru

    2009-03-01

    EUV lithography (EUVL) is a leading candidate for printing sub-32 nm hp patterns. In order for EUVL to be commercially viable at these dimensions, a continuous evolution of the photoresist material set is required to simultaneously meet the aggressive specifications for resolution, resist sensitivity, LWR, and outgassing rate. Alternative PAG designs, especially if tailored for EUVL, may aid in the formation of a material set that helps achieve these aggressive targets. We describe the preparation, characterization, and lithographic evaluation of aryl sulfonates as non-ionic or neutral photoacid generators (PAGs) for EUVL. Full lithographic characterization is reported for our first generation resist formulation using compound H, MAP-1H-2.5. It is benchmarked against MAP-1P-5.0, which contains the well-known sulfonium PAG, triphenylsulfonium triflate (compound P). Z-factor analysis indicates nZ32 = 81.4 and 16.8 respectively, indicating that our first generation aryl sulfonate formulations require about 4.8x improvement to match the results achieved with a model onium PAG. Improving the acid generation efficiency and use of the generated byproducts is key to the continued optimization of this class of PAGs. To that end, we believe EI-MS fragmentation patterns and molecular simulations can be used to understand and optimize the nature and efficiency of electron-induced PAG fragmentation.

  4. Solid Sulfonic Acid Catalysts Based on Porous Carbons and Carbon-Silica Composites

    NASA Astrophysics Data System (ADS)

    Tian, Xiao Ning; Luo, Lijuan; Jiang, Zhongqing; Zhao, X. S.

    Mesoporous carbons prepared using a templating method under different carbonization temperatures are sulfonated with concentrated H2SO4. Without the moving of silica template carbon-silica composites were prepared, which can maintain the pore structure well during sulfonation reaction process. The resultant samples are characterized using nitrogen adsorption, transmission electron microscope, field-emission scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, and elemental analysis techniques. The catalytic performances of the sulfonated carbons and composites are evaluated by esterification reaction of methanol with acetic acid. The results show that a low-temperature carbonization process is favorable for improving the reaction conversion of acetic acid. In addition, the sulfonated carbon-silica composites show a higher acetic acid conversion than the sulfonated mesoporous carbons.

  5. Synthesis and polymerization of substituted ammonium sulfonate monomers for advanced materials applications.

    PubMed

    Cavicchi, Kevin A

    2012-02-01

    Sulfonated polymers have found use as ion-exchange membranes for use in fuel cells, water purification, electroactive devices, and inorganic materials templating and synthesis. Improving the materials for these applications and opening up new applications requires the ability to synthesis targeted or more complex sulfonated polymers, which includes tailoring the chemistry (copolymerization across a wider range of solubility) and/or polymer architecture (block, graft, nanoparticle). This article will summarize the recent work using sulfonated monomers with substituted ammonium counterions as a versatile route for enabling this goal. Two main benefits of these monomers are as follows. First, they are useful for preparing amphiphilic copolymers, which is a challenge using traditional acidic or alkali salt forms of sulfonated monomers. Second, sulfonated polymers with substituted ammonium counterions are useful polymers for obtaining unique material properties, such as organo-gelation of low polarity solvents or obtaining ionic liquid polymers for the fabrication of solid polymer electrolytes.

  6. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  7. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  8. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  9. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  10. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  11. Effect of ion interactions on the IR spectrum of benzenesulfonate ion. Restoration of sulfonate ion symmetry in sodium benzenesulfonate dimer

    NASA Astrophysics Data System (ADS)

    Shishlov, N. M.; Khursan, S. L.

    2016-11-01

    Literature data concerning the assignment of IR spectra of benzenesulfonate salts that serve as model compounds for aromatic sulfonate-containing ionomers and polyelectrolytes have been analyzed. The structures and IR spectra of free benzenesulfonate ion and its potassium and sodium salts have been calculated in B3LYP/6-311G(d,p) approximation. The bidentate coordination of counter-ions is energetically favorable for isolated ion pairs. In this coordination, the symmetry of sulfonate ion changes noticeably, which manifests itself as strong splitting of calculated vibrational modes of asymmetric stretching vibrations of Ssbnd O bonds, Δνas(SO3) = 154 cm-1 (K) and 180 cm-1 (Na). For sodium benzenesulfonate it is thermodynamically favorable to form a dimer (ΔG° = -37.6 kcal/mol) in which the joint effects of monodentate and bidentate coordinated Na cations result in equalization of Ssbnd O bond lengths and thus a considerable restoration of C3V symmetry of the sulfonate ion. The IR spectrum of the dimer in which Δνas(SO3) splitting is considerably smaller much better matches the experimental spectrum than the spectrum of an isolated ion pair. The major absorption bands in the IR spectrum of sodium benzenesulfonate have been assigned to theoretical vibrational modes of the dimer and, based on visualization of modes, to vibrations of certain bonds in the anion. In particular, the bands at 1200 and 1186 cm-1 have been assigned to νas(SO3), that at 1049 cm-1 to νs(SO3), and those at 628 and 572 cm-1 to δ(oop)s(SO3), and δ(ip)as(SO3), respectively. The strong effect of sulfonate ion environment on the positions of the absorption bands of stretching vibrations of Ssbnd O bonds makes it necessary to obtain data on exact structures of ion clusters for reliable assignment of absorption bands in experimental IR spectra of real sulfonate-containing systems.

  12. A simple LC-MS/MS method to determine plasma and cerebrospinal fluid levels of albendazole metabolites (albendazole sulfoxide and albendazole sulfone) in patients with neurocysticercosis.

    PubMed

    González-Hernández, Iliana; Ruiz-Olmedo, María Isabel; Cárdenas, Graciela; Jung-Cook, Helgi

    2012-02-01

    The development and validation of an LC-MS/MS method for the simultaneous determination of albendazole metabolites (albendazole sulfoxide and albendazole sulfone) in human plasma are described. Samples of 200 μL were extracted with ether-dichloromethane-chloroform (60:30:10, v/v/v). The chromatographic separation was performed using a C(18) column with methanol-formic acid 20 mmol/L (70:30) as the mobile phase. The method was linear in a range of 20-5000 ng/mL for albendazole sulfoxide and 10-1500 ng/mL for albendazole sulfone. For both analytes the method was precise (RSD < 12%) and accurate (RE <7%) with high recovery (>90%). The method was successfully applied to determine the plasma and cerebrospinal fluid levels of albendazole sulfoxide and albendazole sulfone in patients with subarachnoidal neurocysticercosis who received albendazole at 30 mg/kg per day for 7 days. This LC-MS/MS method yielded a quick, simple and reliable protocol for determining albendazole sulfoxide and albendazole sulfone concentrations in plasma and cerebrospinal fluid samples and is applicable to therapeutic monitoring.

  13. Preparation of vinylogous 2-sulfonylindolines by the palladium-catalyzed heteroannulation of o-iodoanilines with dienyl sulfones and their further transformation to indoles and carbazoles.

    PubMed

    Back, T G; Bethell, R J; Parvez, M; Taylor, J A

    2001-12-14

    The palladium-catalyzed heteroannulation of o-iodoanilines with dienyl sulfones provides a convenient route to vinylogous 2-sulfonylindolines 3. The reaction proceeds in DMF/water in the presence of potassium carbonate and catalytic palladium(II) acetate and is compatible with both electron-donating and -withdrawing substituents in the para position of the aniline, and with an alkyl substituent at C-2 of the dienyl sulfone. The indolines underwent oxidation with DDQ to afford the corresponding indoles 4. The latter were then employed as dienes in Diels-Alder reactions with dimethyl acetylenedicarboxylate (DMAD), methyl propiolate, or methyl acrylate. In the case of the latter two dienophiles, the cycloadditions were highly regioselective, affording the corresponding 1,3-products (with respect to the relative positions of the sulfone and ester groups), exclusively. The cycloadducts from acetylenic dienophiles were converted to the corresponding carbazoles by elimination of the sulfone moiety with DBU, and that from methyl acrylate was subjected to reductive desulfonylation and oxidation to the corresponding carbazole with DDQ. The method thus provides access to carbazoles with various substituents at the 3-, 4-, and 6-positions. PMID:11735543

  14. A new strategy for the synthesis of taurine derivatives using the 'safety-catch' principle for the protection of sulfonic acids.

    PubMed

    Seeberger, Sonja; Griffin, Roger J; Hardcastle, Ian R; Golding, Bernard T

    2007-01-01

    The safety-catch principle has been applied for the development of a new method for protecting sulfonic acids. 2,2-Dimethylsuccinic acid was reduced to 2,2-dimethylbutane-1,4-diol, which was selectively silylated to give 4-(tert-butyldiphenylsilanyloxy)-2,2-dimethylbutan-1-ol. Reaction of the latter compound with 2-chloroethanesulfonyl chloride in the presence of triethylamine afforded 4-(tert-butyldiphenylsilyloxy)-2,2-dimethylbutyl ethenesulfonate directly. The ethenesulfonate underwent Michael-type addition with secondary amines to give protected derivatives of taurine (2-aminoethanesulfonic acid). Deprotection was achieved on treatment with tetrabutylammonium fluoride, whereby cleavage of the silicon-oxygen bond led to an intermediate alkoxide that immediately cyclised to 2,2-dimethyltetrahydrofuran with liberation of a sulfonate. Pure sulfonic acids were obtained from the crude product by ion exchange chromatography on a strongly basic resin, which was eluted with aqueous acetic acid. The method developed should be generally applicable to the protection of sulfonic acids and is amenable to a multiparallel format.

  15. Crystal structure of potassium (1R)-d-ribit-1-yl­sulfonate

    PubMed Central

    Haines, Alan H.; Hughes, David L.

    2014-01-01

    The title compound, K+·C5H11O8S− [systematic name: potassium (1R,2R,3R,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate], formed by reaction of d-ribose with potassium hydrogen sulfite in water, crystallizes as colourless plates. The anion has an open-chain structure in which the S atom and the C atoms of the sugar chain, excepting that of the hy­droxy­methyl group, form an essentially all-trans chain; the C atom of the hy­droxy­methyl group lies in a gauche relationship with the three contiguous C atoms. Through complex cation coordination (through seven oxygen atoms of six different anions) and inter­molecular O—H⋯O hydrogen bonding, a three-dimensional bonding network exists in the crystal structure. PMID:25484759

  16. Crystal structure of potassium (1R)-d-ribit-1-yl-sulfonate.

    PubMed

    Haines, Alan H; Hughes, David L

    2014-11-01

    The title compound, K(+)·C5H11O8S(-) [systematic name: potassium (1R,2R,3R,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate], formed by reaction of d-ribose with potassium hydrogen sulfite in water, crystallizes as colourless plates. The anion has an open-chain structure in which the S atom and the C atoms of the sugar chain, excepting that of the hy-droxy-methyl group, form an essentially all-trans chain; the C atom of the hy-droxy-methyl group lies in a gauche relationship with the three contiguous C atoms. Through complex cation coordination (through seven oxygen atoms of six different anions) and inter-molecular O-H⋯O hydrogen bonding, a three-dimensional bonding network exists in the crystal structure. PMID:25484759

  17. Solid-phase organic synthesis of polyisoprenoid alcohols with traceless sulfone linker.

    PubMed

    Chang, Yi-Fan; Liu, Chen-Yu; Guo, Chih-Wei; Wang, Yen-Chih; Fang, Jim-Min; Cheng, Wei-Chieh

    2008-09-19

    Solid-phase organic synthesis of polyprenols with a traceless sulfone linker is described. The polymer-bound benezenesulfinate is first linked with the "tail" building blocks of isoprenyl chlorides via S-alkylation. With use of dimsyl anion as an appropriate base, the polymer-bound alpha-sulfonyl carbanion is generated and coupled with other "body" building blocks in an efficient manner. After repeated processes and a global palladium-catalyzed desulfonation with LiEt 3BH as the reducing agent, the desired polyprenols with various chain lengths and geometrical configurations are obtained in 32-59% overall yields. The solid-phase synthesis offers the advantage in facile isolation of polyprenols without tedious operation or time-consuming purification.

  18. Simultaneous determination of perfluoroalkyl phosphonates, carboxylates, and sulfonates in drinking water.

    PubMed

    Ullah, Shahid; Alsberg, Tomas; Berger, Urs

    2011-09-16

    A trace analytical method based on high performance liquid chromatography coupled to quadrupole time-of-flight high resolution mass spectrometry was developed for simultaneous determination of perfluoroalkyl phosphonates (PFPAs, carbon chain lengths C6,8,10), perfluoroalkyl carboxylates (PFCAs, C5-12), and perfluoroalkyl sulfonates (PFSAs, C4,6,8,10) in drinking water (tap water). Analytes were enriched on a mixed mode co-polymeric sorbent (C8+quaternary amine) using solid phase extraction. Chromatographic separation was achieved on a Zorbax Extend C18 reversed phase column using a mobile phase gradient consisting of water, methanol, and acetonitrile containing 2mM ammonium acetate and 5 mM 1-methyl piperidine. The mass spectrometer was operated in electrospray negative ion mode. Use of 1-methyl piperidine in the mobile phase resulted in a significant increase in instrument sensitivity for PFPAs through improved chromatographic resolution, background suppression, and increased ionization efficiency. Method detection limits for extraction of 500 mL tap water were in the ranges of 0.095-0.17 ng/L, 0.027-0.17 ng/L, and 0.014-0.052 ng/L for PFPAs, PFCAs, and PFSAs, respectively. Whole method recoveries at a spiking level of 0.5 ng/L to 500 mL HPLC grade water were 40-56%, 56-97%, and 55-77% for PFPAs, PFCAs, and PFSAs, respectively. A matrix effect (signal enhancement) was observed in the detection of PFPAs in tap water extracts, leading to calculated recoveries of 249-297% at a 0.5 ng/L spiking level. This effect resulted in an additional improvement of method sensitivity for PFPAs. To compensate for the matrix effect, PFPAs in tap water were quantified using matrix-matched and extracted calibration standards. The method was successfully applied to the analysis of drinking water collected from six European countries. PFPAs were not detected except for perfluorooctyl phosphonate (PFOPA) at close to the detection limit of 0.095 ng/L in two water samples from Amsterdam

  19. Crystal structures of three N-(aryl-sulfon-yl)-4-fluoro-benzamides.

    PubMed

    Suchetan, P A; Naveen, S; Lokanath, N K; Srivishnu, K S; Supriya, G M; Lakshmikantha, H N

    2016-04-01

    The crystal structures of three N-aryl-sulfonyl-4-fluoro-benzamides, namely 4-fluoro-N-(2-methyl-phenyl-sulfon-yl)benzamide, C14H12FNO3S, (I), N-(2-chloro-phenyl-sulfon-yl)-4-fluorobenzamide, C13H9ClFNO3S, (II), and N-(4-chloro-phenyl-sulfon-yl)-4-fluoro-benzamide monohydrate, C13H9ClFNO3S·H2O, (III), are described and compared with related structures. The asymmetric unit of (I) contains two independent mol-ecules (A and B), while that of (II) contains just one mol-ecule, and that of (III) contains a mol-ecule of water in addition to one main mol-ecule. The dihedral angle between the benzene rings is 82.83 (11)° in mol-ecule A and 85.01 (10)° in mol-ecule B of (I), compared to 89.91 (10)° in (II) and 81.82 (11)° in (III). The crystal structure of (I) features strong N-H⋯O hydrogen bonds between the A and B mol-ecules, resulting in an R 4 (4)(16) tetra-meric unit. These tetra-meric units are connected into sheets in the bc plane by various C-H⋯O inter-actions, and adjacent sheets are further inter-linked via C-H⋯πar-yl inter-actions, forming a three-dimensional architecture. The crystal structure is further stabilized by πar-yl-πar-yl and S=O⋯πar-yl inter-actions. In the crystal of (II), mol-ecules are connected into R 2 (2)(8) and R 2 (2)(14) dimers via N-H⋯O hydrogen bonds and C-H⋯O inter-actions, respectively; the dimers are further inter-connected via a weak C=O⋯πar-yl inter-action, leading to the formation of chains along [1-10]. In the crystal of (III), N-H⋯O and O-H⋯O hydrogen bonds involving both the main mol-ecule and the solvent water mol-ecule results in the formation of sheets parallel to the bc plane. The sheets are further connected by C-H⋯O inter-actions and weak C-Cl⋯πar-yl, C-F⋯πar-yl and S=O⋯πar-yl inter-actions, forming a three-dimensional architecture.

  20. Sulfonated methyl esters of fatty acids in aqueous solutions: Interfacial and micellar properties.

    PubMed

    Danov, Krassimir D; Stanimirova, Rumyana D; Kralchevsky, Peter A; Basheva, Elka S; Ivanova, Veronika I; Petkov, Jordan T

    2015-11-01

    The interest to sulfonated methyl esters of fatty acids (SME) has been growing during the last decade, because these surfactants are considered as an environmentally friendly and renewable alternative of the linear alkyl-benzene sulfonates (LAS). Here, we present a quantitative study on the properties of aqueous SME solutions, and especially on their surface tension isotherms, critical micelle concentration (CMC) and its dependence on the concentration of added NaCl. It is demonstrated that the CMC of an ionic surfactant determined by electrical conductivity is insensitive to the presence of a small nonionic admixture, so that the CMC values determined by conductivity represent the CMC of the pure surfactant. Using SME as an example, we have demonstrated the application of a new and powerful method for determining the physicochemical parameters of the pure ionic surfactant by theoretical data analysis ("computer purification") if the used surfactant sample contains nonionic admixtures, which are present as a rule. This method involves fits of the experimental data for surface tension and conductivity by a physicochemical model based on a system of mass-balance, chemical-equilibrium and electric-double-layer equations, which allows us to determine the adsorption and micellization parameters of C12-, C14-, C16- and C18-SME, as well the fraction of nonionic admixtures (if any). Having determined these parameters, we can further predict the interfacial and micellization properties of the surfactant solutions, such as surface tension, adsorption, degree of counterion binding, and surface electric potential at every surfactant, salt and co-surfactant concentrations.

  1. Sulfonated methyl esters of fatty acids in aqueous solutions: Interfacial and micellar properties.

    PubMed

    Danov, Krassimir D; Stanimirova, Rumyana D; Kralchevsky, Peter A; Basheva, Elka S; Ivanova, Veronika I; Petkov, Jordan T

    2015-11-01

    The interest to sulfonated methyl esters of fatty acids (SME) has been growing during the last decade, because these surfactants are considered as an environmentally friendly and renewable alternative of the linear alkyl-benzene sulfonates (LAS). Here, we present a quantitative study on the properties of aqueous SME solutions, and especially on their surface tension isotherms, critical micelle concentration (CMC) and its dependence on the concentration of added NaCl. It is demonstrated that the CMC of an ionic surfactant determined by electrical conductivity is insensitive to the presence of a small nonionic admixture, so that the CMC values determined by conductivity represent the CMC of the pure surfactant. Using SME as an example, we have demonstrated the application of a new and powerful method for determining the physicochemical parameters of the pure ionic surfactant by theoretical data analysis ("computer purification") if the used surfactant sample contains nonionic admixtures, which are present as a rule. This method involves fits of the experimental data for surface tension and conductivity by a physicochemical model based on a system of mass-balance, chemical-equilibrium and electric-double-layer equations, which allows us to determine the adsorption and micellization parameters of C12-, C14-, C16- and C18-SME, as well the fraction of nonionic admixtures (if any). Having determined these parameters, we can further predict the interfacial and micellization properties of the surfactant solutions, such as surface tension, adsorption, degree of counterion binding, and surface electric potential at every surfactant, salt and co-surfactant concentrations. PMID:26196714

  2. Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments.

    PubMed

    Baena-Nogueras, Rosa María; Rojas-Ojeda, Patricia; Sanz, José Luis; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2014-06-01

    This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges. We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains (from up to 141 L kg(-1) for C14 to up to 1753 L kg(-1) for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive β-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals.

  3. A diet with lactosucrose supplementation ameliorates trinitrobenzene sulfonic acid-induced colitis in rats.

    PubMed

    Zhou, Yan; Ruan, Zheng; Zhou, Xiaoli; Huang, Xiaoliu; Li, Hua; Wang, Ling; Zhang, Cui; Liu, Shiqiang; Deng, Zeyuan; Wu, Guoyao; Yin, Yulong

    2015-01-01

    Chronic intestinal inflammation contributes to an increased risk of colon cancer. Lactosucrose (LS), a kind of functional trisaccharide, can modulate immunity and promote microbe growth. The aim of this study was to investigate the effect of LS on 2,4,6-trinitrobenzene sulfonic acid (TNBS) induced colitis in rats. Rats were randomly divided into four treatment groups: the normal group, TNBS group, LS group, and salicylazosulfapyridine (SASP) group for five weeks. LS supplementation ameliorated TNBS-induced colitis. LS supplementation increased IL-10 production and suppressed the secretion of IL-12 in the colon, as compared to the TNBS group. LS decreased the production of TLR-2 protein and nuclear NF-κB p65 protein, as well as mRNA levels, as compared with colitic rats. These results indicate that chronic feeding of LS inhibited TNBS-induced chronic inflammation. LS has potential nutraceutical intervention to combat colitis.

  4. Virus concentration using sulfonated magnetic beads to improve sensitivity in nucleic acid amplification tests.

    PubMed

    Iwata, Akiko; Satoh, Koei; Murata, Mitsuhiro; Hikata, Mikio; Hayakawa, Takao; Yamaguchi, Teruhide

    2003-08-01

    To enhance the sensitivity of virus detection by polymerase chain reaction (PCR) and reverse-transcriptional (RT)-PCR, we developed a novel virus-concentration method using sulfonated (SO-) magnetic beads in the presence of divalent cations. In the presence of either Zn(2+) or Cu(2+) ions, we showed that SO-magnetic beads were able to concentrate non-enveloped model viruses, such as porcine parvovirus (PPV) and poliovirus, which were not concentrated by polyethyleneimine (PEI)-magnetic beads.(1)) Using the SO-magnetic beads, the sensitivity of virus genome detection by PCR or RT-PCR can be enhanced. Therefore, an efficient virus concentration method using either SO-magnetic beads or PEI-magnetic beads enhances the sensitivity of virus detection by PCR or RT-PCR.

  5. Nanoscale Distribution of Sulfonic Acid Groups Determines Structure and Binding of Water in Nafion Membranes

    PubMed Central

    Ling, Xiao; Bonn, Mischa

    2016-01-01

    Abstract The connection between the nanoscale structure of two chemically equivalent, yet morphologically distinct Nafion fuel‐cell membranes and their macroscopic chemical properties is demonstrated. Quantification of the chemical interactions between water and Nafion reveals that extruded membranes have smaller water channels with a reduced sulfonic acid head group density compared to dispersion‐cast membranes. As a result, a disproportionally large amount of non‐bulk water molecules exists in extruded membranes, which also exhibit larger proton conductivity and larger water mobility compared to cast membranes. The differences in the physicochemical properties of the membranes, that is, the chemical constitution of the water channels and the local water structure, and the accompanying differences in macroscopic water and proton transport suggest that the chemistry of nanoscale channels is an important, yet largely overlooked parameter that influences the functionality of fuel‐cell membranes. PMID:26895211

  6. Assessment of perfluorooctanoic acid and perfluorooctane sulfonate in surface water - Tamil Nadu, India.

    PubMed

    Sunantha, Ganesan; Vasudevan, Namasivayam

    2016-08-15

    As an emerging class of environmentally persistent organic pollutants, perfluorinated compounds (PFCs), particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); have been universally found in the environment. Wastewater and untreated effluents are likely the major causes for the accumulation of PFCs in surface water. There are very few reports on the contamination of PFCs in the developing countries, particularly in India. This study reports the quantitative analysis of PFOA and PFOS in Noyyal, Cauvery, and also lakes in and around Chennai, using Ultra-Fast liquid chromatograph. The concentration of PFOA and PFOS ranged from 4 to 93ng/L and 3 to 29ng/L, respectively. The concentration of PFOS was below detectable limit in Cauvery River. A reliable concentration of PFOA was recorded at all sites of River Cauvery (5ng/L). The present study could be useful for the assessment of future monitoring programs of PFOA and PFOS in the surface water.

  7. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    SciTech Connect

    Singh, J.; Devi, S. )

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  8. Inhibition of mild steel corrosion by sodium dodecyl benzene sulfonate and sodium oleate in acidic solutions

    SciTech Connect

    Luo, H.; Han, K.N.; Guan, Y.C.

    1998-08-01

    Inhibition of mild steel corrosion by sodium dodecyl benzene sulfonate (C{sub 12}H{sub 25}C{sub 6}H{sub 4}SO{sub 3}Na [SDBS]) and sodium oleate (CH{sub 3}[CH{sub 2}]{sub 7}CH{double_bond}CH[CH{sub 2}]{sub 7}COONa) in acidic solutions was investigated using a potentiostat, a lock-in amplifier, a contact angle goniometer, A fourier transform infrared (FTIR) spectrometer, and an ultraviolet (UV)/visible spectrophotometer. In the presence of the organic inhibitors, the corrosion rate was reduced significantly, Anionic SDBS was adsorbed on the positively charged mild steel surface through the electrostatic attraction. However, for sodium oleate, the soluble oleic acid (CH{sub 3}[CH{sub 2}]{sub 7}CH{double_bond}CH[CH]{sub 7}COOH) chemisorbed on the steel surface at the first stage. Then, insoluble colloid adsorbed on the chemisorbed surface through van der Waals forces.

  9. Nanoscale Distribution of Sulfonic Acid Groups Determines Structure and Binding of Water in Nafion Membranes.

    PubMed

    Ling, Xiao; Bonn, Mischa; Parekh, Sapun H; Domke, Katrin F

    2016-03-14

    The connection between the nanoscale structure of two chemically equivalent, yet morphologically distinct Nafion fuel-cell membranes and their macroscopic chemical properties is demonstrated. Quantification of the chemical interactions between water and Nafion reveals that extruded membranes have smaller water channels with a reduced sulfonic acid head group density compared to dispersion-cast membranes. As a result, a disproportionally large amount of non-bulk water molecules exists in extruded membranes, which also exhibit larger proton conductivity and larger water mobility compared to cast membranes. The differences in the physicochemical properties of the membranes, that is, the chemical constitution of the water channels and the local water structure, and the accompanying differences in macroscopic water and proton transport suggest that the chemistry of nanoscale channels is an important, yet largely overlooked parameter that influences the functionality of fuel-cell membranes.

  10. Identification of a new sulfonic acid metabolite of metolachlor in soil

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.; Yockel, M.E.; Zimmerman, L.R.; Williams, T.D.

    1996-01-01

    An ethanesulfonic acid metabolite of metolachlor (metolachlor ESA) was identified in soil-sample extracts by negative-ion, fast-atom bombardment mass spectrometry (FAB-MS) and FAB tandem mass spectrometry (FAB-MS/MS). Production fragments from MS/MS analysis of the deprotonated molecular ion of metolachlor ESA in the soil extract can be reconciled with the structure of the synthesized standard. The elemental compositions of the (M - H)- ions of the metolachlor ESA standard and the soil-sample extracts were confirmed by high-resolution mass spectrometry. A dissipation study revealed that metolachlor ESA is formed in soil under field conditions corresponding to a decrease in the concentration of the parent herbicide, metolachlor. The identification of the sulfonated metabolite of metolachlor suggests that the glutathione conjugation pathway is a common detoxification pathway shared by chloroacetanilide herbicides.

  11. Evaluation of linear dodecyl benzene sulfonic acid as a teat dip in a commercial dairy.

    PubMed

    Pankey, J W; Boddie, R L; Philpot, W N

    1984-06-01

    A postmilking teat dip containing 1.94% linear dodecyl benzene sulfonic acid was evaluated for approximately 6 mo on a commercial dairy farm that milked an average of 75 cows. Sixteen Staphylococcus aureus infections were diagnosed, 12 in the undipped control quarters and 4 in the dipped. Incidence of intramammary infection with Staphylococcus aureus was reduced 68.1%. Seventy-five infections were diagnosed as micrococci, 42 in control and 33 in the dipped group, a 23.6% reduction. A total of 37 Corynebacterium sp. infections were diagnosed, 21 and 16 in control and dipped groups, a 25.8% reduction. Teat skin condition did not change during the study. PMID:6747046

  12. Sulfone and phosphinic acid analogs of decaprenolphosphoarabinose as potential anti-tuberculosis agents.

    PubMed

    Centrone, Charla A; Lowary, Todd L

    2004-11-01

    Mycobacteria biosynthesize a cell wall structure that is rich in polysaccharides containing arabinofuranose residues. The source of these arabinofuranose residues is decaprenolphosphoarabinose (1), the donor substrate for mycobacterial arabinosyltransferases. We have previously demonstrated that an analog of 1, C-phosphonate 7, prevented the growth of mycobacteria and this compound is currently undergoing testing for efficacy in tuberculosis-infected mice. We describe here the synthesis and testing of additional analogs of 1 that contain either a sulfone (8-14) or phosphinic acid (15-19) moiety in place of the phosphodiester functionality. Screening of these compounds in vitro against Mycobacterium tuberculosis strain H(37)Rv revealed that while some of these compounds possessed low to modest activity, none was as potent as 7.

  13. Chemical doping of MoS2 multilayer by p-toluene sulfonic acid

    NASA Astrophysics Data System (ADS)

    Andleeb, Shaista; Singh, Arun Kumar; Eom, Jonghwa

    2015-06-01

    We report the tailoring of the electrical properties of mechanically exfoliated multilayer (ML) molybdenum disulfide (MoS2) by chemical doping. Electrical charge transport and Raman spectroscopy measurements revealed that the p-toluene sulfonic acid (PTSA) imposes n-doping in ML MoS2. The shift of threshold voltage for ML MoS2 transistor was analyzed as a function of reaction time. The threshold voltage shifted toward more negative gate voltages with increasing reaction time, which indicates an n-type doping effect. The shift of the Raman peak positions was also analyzed as a function of reaction time. PTSA treatment improved the field-effect mobility by a factor of ~4 without degrading the electrical characteristics of MoS2 devices.

  14. Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments.

    PubMed

    Baena-Nogueras, Rosa María; Rojas-Ojeda, Patricia; Sanz, José Luis; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2014-06-01

    This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges. We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains (from up to 141 L kg(-1) for C14 to up to 1753 L kg(-1) for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive β-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals. PMID:24631971

  15. Study on the interaction of sodium morin-5-sulfonate with bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Mohammadpour, Mahnaz

    2012-02-01

    In the present investigation, an attempt has been made to study the interaction of sodium morin-5-sulfonate (NaMSA) with the transport proteins, bovine serum albumin (BSA) employing UV-vis, fluorometric and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the compound was a static procedure. Various binding parameters were evaluated. The negative value of Δ H, positive value of Δ S and the negative value of Δ G indicated that electrostatic interactions and hydrogen bonding play major roles in the binding of the NaMSA and BSA. Based on the Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (NaMSA) was evaluated. The results of CD and UV-vis spectroscopy showed that the binding of this complex to BSA induces some conformational changes in BSA.

  16. Morphological investigation of midblock-sulfonated block ionomers prepared from solvents differing in polarity.

    PubMed

    Mineart, Kenneth P; Jiang, Xi; Jinnai, Hiroshi; Takahara, Atsushi; Spontak, Richard J

    2015-03-01

    Recent developments regarding charged multiblock copolymers that can form physical networks and exhibit robust mechanical properties herald new and exciting opportunities for contemporary technologies requiring amphiphilic attributes. Due to the presence of strong interactions, however, control over the phase behavior of such materials remains challenging, especially since their morphologies can be solvent-templated. In this study, transmission electron microscopy and microtomography are employed to examine the morphological characteristics of midblock-sulfonated pentablock ionomers prepared from solvents differing in polarity. Resultant images confirm that discrete, spherical ion-rich microdomains form in films cast from a relatively nonpolar solvent, whereas an apparently mixed morphology with a continuous ion-rich pathway is generated when the casting solvent is more highly polar. Detailed 3D analysis of the morphological characteristics confirms the coexistence of hexagonally-packed nonpolar cylinders and lamellae, which facilitates the diffusion of ions and/or other polar species through the nanostructured medium.

  17. Method of increasing enhanced oil recovery by using a novel low sulfonate phase in the polymer slug

    SciTech Connect

    Carlin, J.T.; Haferkamp, G.L.

    1987-03-10

    A process is described for enhanced hydrocarbon recovery comprising injecting into a well a surfactant fluid comprising the fraction having the highest sulfonate content which separates after settling from a mixture of water, petroleum sulfonate surfactant, solubilizer and polymer. Thereafter the remaining fraction of surfactant fluid which contains the lower sulfonate content is added to a polymer slug, injecting the polymer slug and forcing the high sulfonate content surfactant slug and subsequently the low sulfonate polymer slug through the formation and recovering the hydrocarbons.

  18. Fully aromatic block copolymers for fuel cell membranes with densely sulfonated nanophase domains.

    PubMed

    Takamuku, Shogo; Jannasch, Patric

    2011-03-01

    Two multiblock copoly(arylene ether sulfone)s with similar block lengths and ion exchange capacities (IECs) were prepared by a coupling reaction between a non-sulfonated precursor block and a highly sulfonated precursor block containing either fully disulfonated diarylsulfone or fully tetrasulfonated tetraaryldisulfone segments. The latter two precursor blocks were sulfonated via lithiation-sulfination reactions whereby the sulfonic acid groups were exclusively placed in ortho positions to the many sulfone bridges, giving these blocks IECs of 4.1 and 4.6 meq·g⁻¹, respectively. Copolymer membranes with IECs of 1.4 meq·g⁻¹ displayed well-connected hydrophilic nanophase domains and had decomposition temperatures at, or above, 300 °C under air. The copolymer with the tetrasulfonated tetraaryldisulfone segments showed a proton conductivity of 0.13 S·cm⁻¹ at 80 °C under fully humidified conditions, and surpassed that of a perfluorosulfonic acid membrane (NRE212) by a factor of 5 at -20 °C over time.

  19. Celecoxib influences steroid sulfonation catalyzed by human recombinant sulfotransferase 2A1

    PubMed Central

    Ambadapadi, Sriram; Wang, Peter L.; Palii, Sergiu P.; James, Margaret O.

    2015-01-01

    Celecoxib has been reported to switch the human SULT2A1-catalyzed sulfonation of 17βestradiol (17β-E2) from the 3- to the 17-position. The effects of celecoxib on the sulfonation of selected steroids catalyzed by human SULT2A1 were assessed through in vitro and in silico studies. Celecoxib inhibited SULT2A1-catalyzed sulfonation of dehydroepiandrosterone (DHEA), androst-5-ene-3β, 17β-diol (AD), testosterone (T) and epitestosterone (Epi-T) in a concentration-dependent manner. Low μM concentrations of celecoxib strikingly enhanced the formation of the 17-sulfates of 6-dehydroestradiol (6D-E2), 17β-dihydroequilenin (17β-Eqn), 17β-dihydroequilin (17β-Eq), and 9-dehydroestradiol (9D-E2) as well as the overall rate of sulfonation. For 6D-E2, 9D-E2 and 17β-Eqn, celecoxib inhibited 3-sulfonation, however 3-sulfonation of 17β-Eq was stimulated at celecoxib concentrations below 40 μM. Ligand docking studies in silico suggest that celecoxib binds in the substrate-binding site of SULT2A1 in a manner that prohibits the usual binding of substrates but facilitates, for appropriately shaped substrates, a binding mode that favors 17-sulfonation. PMID:25960318

  20. Electrochemical Studies of Ceramic Carbon Electrodes Prepared with Sulfonated Organosilane Precursors

    NASA Astrophysics Data System (ADS)

    Eastcott, Jennie

    State-of-the-art electrodes for proton exchange membrane fuel cells (PEMFCs) contain platinum catalyst and a Nafion proton-conducting binder. Optimal conditions for Nafion functionality are at 80°C and 100% relative humidity (RH). Ceramic carbon electrodes (CCEs), consisting of carbon particles supported by ceramic binder network, may be an alternative electrode structure which replaces Nafion with organosilane materials. CCEs are also attractive for their high surface area and durable nature. CCEs have been fabricated via an in-situ sol-gel polymerization process. Development of a novel electrode fabrication procedure included direct spray-deposition of CCEs onto a microporous/gas diffusion layer to facilitate adhesion and facile electrode preparation. CCEs were composed of commercial carbon-supported platinum catalyst and 3-trihydroxysilyl-1-propanesulfonic acid (TPS) or TPS and tetraethylorthosilicate (TEOS) to vary the level of sulfonation. CCEs were initially tested electrochemically in a half-cell set-up to evaluate electrode functionality. An optimal loading of 42-48 wt% silane was determined for CCEs with only TPS to provide the highest electrochemically active surface area (ECSA) of platinum and proton conductivity. BET surface areas were low due to restriction of pore sizes by the sulfonated side chain. Composite CCEs of TPS/TEOS had enhanced electrochemical performance and high BET surface areas (>400 m 2 g-1), indicating high porosity. Excellent electrochemical results were obtained for the CCE with a TPS:TEOS ratio of 4:96 (40 wt% total silane). The sulfonated TPS/TEOS CCE (SS-CCE) was further evaluated in a fuel cell. Electrochemical studies showcased higher accessibility of catalyst sites and good proton conductivity compared to Nafion-containing cathodes. At 80°C and 100% relative humidity (RH), CCEs performed similarly to Nafion electrodes at low current density but suffered from mass transport limitations due to flooding at high current density

  1. A model survey meter using undoped poly (ether sulfone)

    NASA Astrophysics Data System (ADS)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Kanayama, Masaya; Sato, Nobuhiro; Kitamura, Hisashi; Takahashi, Sentaro

    2015-04-01

    The large region surrounding the damaged Fukushima Daiichi Nuclear Power Plant has necessitated the use of numerous radiation survey meters with large, robust substrates. The survey meters require efficient scintillation materials that do not require doping and have dimensional stability, such as poly (ether sulfone) (PES) resins. Here, we demonstrate the performance of a model survey meter that uses large PES plates with polished, mirrored surfaces and rough, scattering surfaces. Light collection efficiencies from plates having one or more of these surfaces were quantitatively Characterised with 36Cl-, 60Co-, 137Cs-radioactive sources. The count rates of plates having a combination of mirrored/scattering-surfaces are >1.6 times that for plates having two mirrored surfaces. In addition, a significant amount of radiation-induced light generated in the PES is trapped inside the plate because of its relatively high refractive index. The results indicate that large, undoped PES plates can be used in radiation survey meters.

  2. Layered solids based on second-sphere coordination interactions: synthesis, spectroscopic characterization, crystal structure and packing of two copper(II) naphthalene-2-sulfonates

    NASA Astrophysics Data System (ADS)

    Sharma, Raj Pal; Sharma, Rajni; Bala, Ritu; Rychlewska, Urszula; Warżajtis, Beata

    2005-03-01

    [Cu(H 2O) 6](C 10H 7SO 3) 21 was obtained from reaction of CuCO 3·Cu(OH) 2 and naphthalene-2-sulphonic acid in aqueous medium in 1:4 molar ratio. It crystallizes in the monoclinic space group P2 1/ n with a=7.0582(3) Å, b=6.2666(3) Å, and c=27.1420(10) Å, β=92.678(4)°, Z=2. The structure was determined from 1986 observed reflections and refined to R=0.033. When ethylenediamine was added to hexaaquacopper(II) naphthalene-2-sulfonate dissolved in water, [Cu(en) 2(H 2O) 2](C 10H 7SO 3) 22 was obtained which crystallizes in the triclinic space group P1¯ with a=7.1491(5) Å, b=7.1949(5) Å, and c=14.6500(10) Å, α=99.025(6)°, β=98.976(6)°, and γ=104.262(6)°, Z=1. The structure was determined from 2296 observed reflections and refined to R=0.0313. X-ray structure determination of 1 revealed an ionic structure consisting of [Cu(H 2O) 6] +2 and two naphthalene-2-sulfonate anions while that of 2 contains [Cu(en) 2(H 2O) 2] 2+ cation and two naphthalene-2-sulfonate anions. Characteristic for the studied crystals is the alternated-layer arrangement of complex cations and naphthalene-2-sulfonate anions, linked together via hydrogen bonding, and the presence of a particularly robust R22(8) hydrogen-bonding motif that joins the complex cation with two oxygen atoms of the same sulfonate group. Elemental analyses, IR, UV/vis spectroscopic studies are consistent with the structures revealed by X-ray structure determination.

  3. Aerobic Biotransformation of Fluorotelomer Thioether Amido Sulfonate (Lodyne) in AFFF-Amended Microcosms.

    PubMed

    Harding-Marjanovic, Katie C; Houtz, Erika F; Yi, Shan; Field, Jennifer A; Sedlak, David L; Alvarez-Cohen, Lisa

    2015-07-01

    The aerobic biotransformation pathways of 4:2, 6:2, and 8:2 fluorotelomer thioether amido sulfonate (FtTAoS) were characterized by determining the fate of the compounds in soil and medium microcosms amended with an aqueous film-forming foam (AFFF) solution. The biotransformation of FtTAoS occurred in live microcosms over approximately 40 days and produced 4:2, 6:2, and 8:2 fluorotelomer sulfonate (FtS), 6:2 fluorotelomer unsaturated carboxylic acid (FtUCA), 5:3 fluorotelomer carboxylic acid (FtCA), and C4 to C8 perfluorinated carboxylic acids (PFCAs). Two biotransformation products corresponding to singly and doubly oxygenated forms of 6:2 FtTAoS were also identified through high resolution mass spectrometry (MS) analysis and liquid chromatography tandem-MS. An oxidative assay was used to indirectly quantify the total concentration of polyfluorinated compounds and check the mass balance. The assay produced near complete mass recovery of FtTAoS after biotransformation, with 10% (mol/mol) of the amended FtTAoS accounted for in FtS, FtCA, and PFCA products. The transformation rates of identified products appear to be slow relative to FtTAoS, indicating that some intermediates may persist in the environment. This study confirms some of the sources of FtS and PFCAs in groundwater and soil at AFFF-impacted sites and suggests that fluorinated intermediates that are not routinely measured during the biotransformation of PFASs may accumulate. PMID:26042823

  4. Design, fabrication and evaluation of intelligent sulfone-selective polybenzimidazole nanofibers.

    PubMed

    Ogunlaja, Adeniyi S; du Sautoy, Carol; Torto, Nelson; Tshentu, Zenixole R

    2014-08-01

    Molecularly imprinted polybenzimidazole nanofibers fabricated for the adsorption of oxidized organosulfur compounds are presented. The imprinted polymers exhibited better selectivity for their target model sulfone-containing compounds with adsorption capacities of 28.5±0.4mg g(-1), 29.8±2.2mg g(-1) and 20.1±1.4mg g(-1) observed for benzothiophene sulfone (BTO2), dibenzothiophene sulfone (DBTO2) and 4,6-dimethyldibenzothiophene sulfone (4,6-DMDBTO2) respectively. Molecular modeling based upon the density functional theory (DFT) indicated that hydrogen bond interactions may take place between sulfone oxygen groups with NH groups of the PBI. Further DFT also confirmed the feasibility of π-π interactions between the benzimidazole rings and the aromatic sulfone compounds. The adsorption mode followed the Freundlich (multi-layered) adsorption isotherm which indicated possible sulfone-sulfone interactions. A home-made pressurized hot water extraction (PHWE) system was employed for the extraction/desorption of sulfone compounds within imprinted nanofibers at 1mL min(-1), 150°C and 30 bar. PHWE used a green solvent (water) and achieved better extraction yields compared to the Soxhlet extraction process. The application of molecularly imprinted polybenzimidazole (PBI) nanofibers displayed excellent sulfur removal, with sulfur in fuel after adsorption falling below the determined limit of detection (LOD), which is 2.4mg L(-1)S, and with a sulfur adsorption capacity of 5.3±0.4mg g(-1) observed for application in the fuel matrix.

  5. Catalytic conjugate additions of geminal bis(sulfone)s: expanding the chemistry of sulfones as simple alkyl anion equivalents.

    PubMed

    Landa, Aitor; Puente, Angel; Santos, J Ignacio; Vera, Silvia; Oiarbide, Mikel; Palomo, Claudio

    2009-11-01

    The value of cyclic gem-bis(sulfone) 4 as a simple alkyl nucleophile equivalent in catalytic C-C bond-forming reactions is demonstrated. The 1,4-type nucleophilic additions of bis(sulfone) 4 to alpha,beta-unsaturated ketones take place by assistance of catalytic guanidine base. On the other hand, pyrrolidines are able to catalyze the conjugate addition of 4 to both enones and enals, likely by means of iminium ion activation. Upon exploration of the best chiral pyrrolidine catalyst, it has been found that the addition of 4 to enals catalyzed by diphenylprolinol silyl ether 10 proceeds with very high enantioselectivity (beta-aryl-substituted enals >95% ee; beta-alkyl substituted enals up to 94% ee; ee = enantiomeric excess). Further reductive desulfonation of adducts gives rise to the corresponding beta-methyl aldehydes, as well as the derived alcohols, acetals, and methyl esters after simple (Mg, MeOH) well-established protocols. Application of the procedure to the synthesis of biologically relevant phenethyl building blocks is shown. Most interestingly, alpha-alkylation of initially obtained bis(sulfone) adducts can be done even with less reactive alkylating reagents, such as long linear-chain or branched-chain alkyl halides. Accordingly, upon the desulfonation process, a general, experimentally simple and highly enantioselective access to beta-branched aldehydes, alcohols, or esters is possible. Further exploration of the method includes the use of chiral alpha,beta-unsaturated aldehydes derived from citronellal as the Michael acceptor partners. In these instances, the sense of the conjugate addition of 4 is controlled by the chirality of the pyrrolidine catalyst, thus allowing for a stereochemically predictable access to 1,3-dimethyl arrays, such as those present in deoxygenated polyketide-type natural products. The intramolecular variation of this technology by using doubly unsaturated aldehyde-ester 22 illustrated the site selectivity of the procedure and its

  6. Phase behavior of 1-alkylpyridinium octane-1-sulfonates. effect of the 1-alkylpyridinium counterion size.

    PubMed

    Persson, Gerd; Edlund, Håkan; Hedenström, Erik; Lindblom, Göran

    2004-02-17

    The temperature-versus-composition phase diagrams of eight different 1-alkylpyridinium octane-1-sulfonates (APOSs) in water were studied by 1H NMR, 2H NMR, pulsed gradient spin-echo NMR, small-angle X-ray diffraction, differential scanning calorimetry, surface tension and conductivity measurements, and polarizing microscopy. The number of carbons (n(c)) in the hydrocarbon chain of the pyridinium counterions was varied from n(c) = 1 to n(c) = 8 to study how the phase behavior of the APOS/2H2O systems was affected by a change in the chain length of the counterion. The sodium octane-1-sulfonate (NaOS)/water system was used as a reference. This system formed an isotropic micellar solution (L1) phase and a normal hexagonal (H(I)) phase. All APOSs were readily soluble in water and formed L1 phases. The surface tension above the critical micelle concentration for n(c) between 1 and 3 was higher than that for NaOS, and it decreased steadily for the different APOSs with increasing chain length. The area per molecule at the air/solution interfaces was rather constant at 68 A2 for n(c) between 1 and 7. For 1-octylpyridinium octane-1-sulfonate (OPOS), it was about 5 A2 smaller, which was just outside the estimated error. However, the smallest area was obtained for NaOS. At higher surfactant concentrations, liquid crystalline phases formed. Both cubic and H(I) phases were found for n(c) = 1 and 2, while for n(c) between 3 and 5 only an H(I) phase was observed. H(I) and lamellar liquid crystalline (Lalpha) phases formed for n(c) = 6 and 7. The only liquid crystalline phase found in the OPOS system was a Lalpha phase. The NaOS H(I) phase was the only liquid crystalline phase that showed a linear relation between the 2H2O NMR quadrupolar splitting (deltaW) and Xsurf/X(W), where Xsurf and X(W) are the mole fractions of surfactant and water. The OPOS lamellae were found to be much thinner than expected, indicating a defect lamellar structure. This was further supported by the

  7. Spectroscopic studies of inclusion complexes of 1-naphthol-4-sulfonate with beta-cyclodextrin in aqueous solution.

    PubMed

    Al-Shihry, Shar S

    2005-09-01

    The photophysical properties of 1-naphthol-4-sulfonate (1N4S) in some solvents and in aqueous beta-cyclodextrin solution have been investigated. The effect of beta-cyclodextrin on the fluorescence quantum yield and on the proton transfer is examined. Fluorescence measurements show 1:1 inclusion of 1N4S in the beta-cyclodextrin cavity with an association constant of 108M(-1). NMR studies are used to study the inclusion phenomena and to provide information on the geometry of 1N4S inside the cavity of beta-cyclodextrin.

  8. Spectroscopic studies of inclusion complexes of 1-naphthol-4-sulfonate with β-cyclodextrin in aqueous solution

    NASA Astrophysics Data System (ADS)

    Al-Shihry, Shar S.

    2005-09-01

    The photophysical properties of 1-naphthol-4-sulfonate (1N4S) in some solvents and in aqueous β-cyclodextrin solution have been investigated. The effect of β-cyclodextrin on the fluorescence quantum yield and on the proton transfer is examined. Fluorescence measurements show 1:1 inclusion of 1N4S in the β-cyclodextrin cavity with an association constant of 108 M -1. NMR studies are used to study the inclusion phenomena and to provide information on the geometry of 1N4S inside the cavity of β-cyclodextrin.

  9. Differences in responsivity of original cupric reducing antioxidant capacity and cupric-bathocuproine sulfonate assays to antioxidant compounds.

    PubMed

    Çelik, S Esin; Ozyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2012-04-01

    The cupric reducing antioxidant capacity (CUPRAC) method using bathocuproine sulfonate (BCS) as cuprous-chelating ligand claims to be an efficient substitute for the conventional CUPRAC assay using neocuproine; however, differences in their physical chemistry give rise to significantly varying responsivities to antioxidant compounds. The antioxidant capacity due to β-carotene (in acetone or dichloromethane) was fully measurable by conventional CUPRAC but not at all by cupric-BCS assay. Furthermore, CUPRAC exhibits distinctly stronger responses than cupric-BCS to naringenin, α-tocopherol, and bilirubin.

  10. Method of increasing enhanced oil recovery by using a higher sulfonate phase obtained on polymer addition

    SciTech Connect

    Carlin, J.T.

    1987-01-13

    A process is described for enhanced hydrocarbon recovery comprising: dissolving a polymer from the group consisting of polyacrylamides and polysaccharides in a surfactant flood fluid resulting from mixing water, petroleum sulfonate-containing surfactant and solubilizer; allowing the mixture to separate; using the fraction with the highest sulfonate content as a surfactant fluid; forcing the fluid through the formation and recovering the hydrocarbons, wherein the proportion of the sulfonate-containing surfactant, solubilizer and polymer is about 0.5% to 20.0% of total solute by weight of petroleum sulfonate surfactant, about 0.1% to about 5% by weight of a solubilizer and about 0.1% to 10% by weight of polymer.

  11. Titania-based molecularly imprinted polymer for sulfonic acid dyes prepared by sol-gel method.

    PubMed

    Li, Man; Li, Rong; Tan, Jin; Jiang, Zi-Tao

    2013-03-30

    A novel titania-based molecularly imprinted polymer (MIP) was synthesized through sol-gel process with sunset yellow (Sun) as template, without use of functional monomer. MIP was used as a solid-phase extraction material for the isolation and enrichment of sulfonic acid dyes in beverages. The results showed that MIP exhibited better selectivity, higher recovery and adsorption capacity for the sulfonic acid dyes compared to the non-imprinted polymer (NIP). MIP presented highest extraction selectivity to Sun when pH less than or equal to 3. The adsorption capacity was 485.9 mg g(-1), which was larger than that of NIP (384.7 mg g(-1)). The better clean-up ability demonstrated the capability of MIP for the isolation and enrichment of sulfonic acid dyes in complicated food samples. The mean recoveries for the sulfonic acid dyes on MIP were from 81.9% to 97.2% in spiked soft drink.

  12. EFFECTS OF PRENATAL PERFLUOROOCTANE SULFONATE (PFOS) EXPOSURE ON LUNG MATURATION IN THE PERINATAL RAT

    EPA Science Inventory

    Background: Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfon...

  13. Magnetite-supported sulfonic acid: a retrievable nanocatalyst for the Ritter reaction and multicomponent reactions

    EPA Science Inventory

    Magnetite-sulfonic acid (NanocatFe-OSO3H), prepared by wet-impregnation method, serves as a magnetically retrievable sustainable catalyst for the Ritter reaction which can be used in several reaction cycles without any loss of activity.

  14. Synthesis and characterizations of electrospun sulfonated poly (ether ether ketone) SPEEK nanofiber membrane

    NASA Astrophysics Data System (ADS)

    Hasbullah, N.; Sekak, K. A.; Ibrahim, I.

    2016-07-01

    A novel electrospun polymer electrolyte membrane (PEM) based on Sulfonated Poly (ether ether ketone) were prepared and characterized. The poly (ether ether ketone) PEEK was sulfonated using concentrated sulfuric acid at room temperature for 60 hours reaction time. The degree sulfonation (DS) of the SPEEK are 58% was determined by H1 NMR using area under the peak of the hydrogen shielding at aromatic ring of the SPEEK. Then, the functional group of the SPEEK was determined using Fourier transfer infrared (FTIR) showed O-H vibration at 3433 cm-1 of the sulfonated group (SO2-OH). The effect of the solvent and polymer concentration toward the electrospinning process was investigated which, the DMAc has electrospun ability compared to the DMSO. While, at 20 wt.% of the polymer concentration able to form a fine and uniform nanofiber, this was confirmed by FESEM that shown electrospun fiber mat SPEEK surface at nano scale diameter.

  15. Effect of sulfonation and diethanolamine addition on the mechanical and physicochemical properties of SEPS copolymer

    NASA Astrophysics Data System (ADS)

    Patiño, D.; Correa, E.; Acevedo-Morantes, M.

    2016-02-01

    Modification techniques have been developed to achieve changes in the processing of polymers, and modification of their mechanical, thermal and morphological properties, as well as their hydrophobicity and conductivity. Sulfonation improves ion conductivity, antistatic behaviour, hydrophilicity and solubility of the polymers. These characteristics are related to the presence of sulfonic groups in the polymer matrix. This research project focuses on the evaluation of mechanical, physical and chemical properties of membranes that are based on a sulfonated Styrene-Ethylene-Propylene-Styrene (SEPS) copolymer. The membranes were functionalized with diethanolamine at 5, 15 and 30% w/w, to separate carbon dioxide. FTIR and XRD analyses were used to characterize the membranes. The sulfonated-loaded membrane with 15% of diethanolamine showed the best results in each characterization.

  16. Anhydrous state proton and lithium ion conducting solid polymer electrolytes based on sulfonated bisphenol-A-poly(arylene ethers)

    NASA Astrophysics Data System (ADS)

    Guha Thakurta, Soma

    Sulfonated polymer based solid polymer electrolytes (SPEs) have received considerable interest in recent years because of their wide variety of applications particularly in fuel cells, batteries, supercapacitors, and electrochromic devices. The present research was focused on three interrelated subtopics. First, two different bisphenol-A-poly(arylene ethers), polyetherimide (PEI) and polysulfone (PSU) were sulfonated by a post sulfonation method to various degrees of sulfonation, and their thermal and mechanical properties were examined. The effects of poly(arylene ether) chemical structure, reaction time, concentration, and types of sulfonating agents on sulfonation reaction were investigated. It was found that deactivation of bisphenol A unit caused by the electron withdrawing imide, retarded the sulfonation of PEI compared to PSU. Sulfonation conducted with a high concentration of sulfonating agent and/or prolonged reaction time exhibited evidence of degradation at the isopropylidene unit. The degradation occurred through the same mechanistic pathway with the two different sulfonating agents, chlorosulfonic acid (CSA) and trimethylsilyl chlorosulfonate (TMSCS). The degradation was faster with CSA than its silyl ester, TMSCS, and was evident even at low acid concentration. Second, novel anhydrous proton conducting solid polymer electrolytes (SPEs) were prepared by the incorporation of 1H-1,2,4-triazole (Taz) as a proton solvent in sulfonated polyetherimide (SPEI) matrix. The size, shape, and state of dispersion (crystal morphology) of triazole crystals in SPEI were examined as a function of degree of sulfonation and triazole concentration. Increasing sulfonic acid content caused reduction of triazole crystallite size, hence the depression of melting temperature and their uniform distribution throughout the sulfonated polymer matrix. The increased rate of structure diffusion within the smaller size crystals due to the improved molecular mobility contributed

  17. Design and Development of Highly Sulfonated Polymers as Proton Exchange Membranes for High Temperature Fuel Cell Applications

    NASA Astrophysics Data System (ADS)

    Dang, Thuy D.; Bai, Zongwu; Yoonessi, Mitra

    A series of high molecular weight, highly sulfonated poly(arylenethioethersulfone) (SPTES) polymers were synthesized by polycondensation, which allowed controlled sulfonation of up to 100 mol %. The SPTES polymers were prepared via step growth polymerization of sulfonated aromatic difluorosulfone, aromatic difluorosulfone, and 4,4 '-thiobisbenzenthiol in sulfolane solvent at the temperature up to 180 °C. The composition and incorporation of the sulfonated repeat unit into the polymers were confirmed by 1H nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. Solubility tests on the SPTES polymers confirmed that no cross-linking and probably no branching occurred during the polymerizations. The end-capping groups were introduced in the SPTES polymers to control the molecular weight distribution and reduce the water solubility of the polymers. Tough, ductile membranes formed via solvent-casting exhibited increased water absorption with increasing degrees of sulfonation. The polymerizations conducted with the introduction of end-capping groups resulted in a wide variation in polymer proton conductivity, which spanned a range of 100 -300 mS cm-1, measured at 65 °C and 85 % relative humidity. The measured proton conductivities at elevated temperatures and high relative humidities are up to three times higher than that of the state-of-the-art Nafion-H proton exchange membrane under nearly comparable conditions. The thermal and mechanical properties of the SPTES polymers were investigated by TGA, DMA, and tensile measurements. The SPTES polymers show high glass transition temperatures (Tg), ˜220 °C, depending on the degree of sulfonation in polymerization. SPTES-50 polymer shows a Tg of 223 °C, with high tensile modulus, high tensile strengths at break and at yield as well as elongation at break. Wide angle X-ray scattering of the polymers shows two broad scattering features centered at 4.5 Å and 3.3 Å, the latter peak being

  18. Synthesis, structure, theoretical calculations and biological activity of sulfonate active ester new derivatives

    NASA Astrophysics Data System (ADS)

    Ghazzali, Mohamed; Khattab, Sherine A. N.; Elnakady, Yasser A.; Al-Mekhlafi, Fahd A.; Al-Farhan, Khalid; El-Faham, Ayman

    2013-08-01

    A series of naphthyl and tolyl sulfonate ester were synthesized and characterized by H NMR. X-ray single crystal diffraction experiments established the molecular structure of three new sulfonate esters derivatives, and spectral data agree with these in solution. The observed hydrogen bonding is discussed on the basis of crystal structural analyses and DFT/MP2 geometry optimization quantum calculations. Antimicrobial activities were screened for selected compounds against three human cancer cell lines and Mosquito Culex pipiens larvae.

  19. Asymmetrical Self-assembly From Fluorinated and Sulfonated Block Copolymers in Aqueous Media

    SciTech Connect

    Wang, Xiaojun; Hong, Kunlun; Baskaran, Durairaj; Goswami, Monojoy; Sumpter, Bobby G; Mays, Jimmy

    2011-01-01

    Block copolymers of fluorinated isoprene and partially sulfonated styrene form novel tapered rods and ribbon-like micelles in aqueous media due to a distribution of sulfonation sites and a large Flory-Huggins interaction parameter. A combination of microscopy, light scattering, and simulation demonstrates the presence of these unique nanostructures. This study sheds light on the micellization behavior of amphiphilic block polymers by revealing a new mechanism of self-assembly.

  20. Sulfonate-cosurfactant mixtures for use in hard brines during oil recovery operations

    SciTech Connect

    Meister, J. J.

    1981-05-12

    Alkyl vinyl ether-maleic anhydride copolymers, alone or in combination with ethoxylated acids and/or ethoxylated amides and, optionally, together with polyalkoxylated carboxylic acids, polyalkoxylated amides and sulfated derivatives thereof, ethoxylated alkyl phenols, ethoxylated alcohols and the corresponding sulfated derivatives, sulfated aliphatic alcohols and alkylene oxide block copolymers, are useful to stabilize sulfonate surfactants, E.G., petroleum sulfonates, E.G., for use in tertiary oil recovery.

  1. Activated-sludge nitrification in the presence of linear and branched-chain alkyl benzene sulfonates.

    PubMed

    Baillod, C R; Boyle, W C

    1968-01-01

    The effects of biodegradable linear alkyl benzene sulfonate and branched-chain alkyl benzene sulfonate detergents on activated-sludge nitrification were investigated by administering a synthetic waste containing up to 23 mg of each detergent per liter to eight bench-scale, batch, activated-sludge units. It was found that both detergents tended to promote complete oxidation of ammonia to nitrate, whereas control units produced approximately equal amounts of nitrite and nitrate. Various hypotheses are offered to explain the phenomenon.

  2. Viscoelastic Behavior of Low Molecular Weight Sulfonated Polystyrene Ionomers

    NASA Astrophysics Data System (ADS)

    Zhao, Hongying

    Ionomers are those hydrophobic polymers having small amounts of bonded ionic groups. The introduction of the ionic groups into polymer chain produces large changes in the physical, mechanical and rheological properties of the parent polymer. Characterization of the effect of the ionic interactions on the rheology is complicated by the difficulty in separating effects due to molecular entanglements and the ionic interactions. In this study, low molecular weight (Mw=4000) sulfonated polystyrene (SPS) was used to study the dynamic and steady shear rheology of SPS ionomers. The polymer chain length used was far below the entanglement molecular weight of polystyrene and effects of molecular entanglements will be absent. Any polymer chain entanglements or lengthening behavior on the melt rheology should be due to the ionic interactions. Random SPS ionomers with two sulfonation levels were examined, 2.5 and 4.8 mol%, which corresponded, respectively, to one and two sulfonate groups per chain on average. The metal counterions was varied across the alkali metal series of the periodic table. Morphology of the ionomer was characterized by using small angle x-ray scattering (SAXS) analysis, and dynamic and steady shear measurements were performed to investigate rheological behavior of the ionomers. Glass transition temperatures of the ionomers increased with increasing ion concentration but were insensitive to cation used. The scattering peak in SAXS indicates the existence of the nanophase separated ionic clusters. The strong ionic nanophase persist up to very high temperatures and is not sensitive to the external stress. Time-temperature superposition (TTS) of G' worked reasonably well while TTS of G" failed for most ionomers. Ionic interactions increased the terminal relaxation time of the melts as much as seven orders of magnitude greater than the unentangled PS melt. The zero shear viscosity and first normal stress coefficients scaled with cq/a, where c was the

  3. Composite proton exchange membrane based on sulfonated organic nanoparticles

    NASA Astrophysics Data System (ADS)

    Pitia, Emmanuel Sokiri

    As the world sets its sight into the future, energy remains a great challenge. Proton exchange membrane (PEM) fuel cell is part of the solution to the energy challenge because of its high efficiency and diverse application. The purpose of the PEM is to provide a path for proton transport and to prevent direct mixing of hydrogen and oxygen at the anode and the cathode, respectively. Hence, PEMs must have good proton conductivity, excellent chemical stability, and mechanical durability. The current state-of-the-art PEM is a perfluorosulfonate ionomer, Nafion®. Although Nafion® has many desirable properties, it has high methanol crossover and it is expensive. The objective of this research was to develop a cost effective two-phase, composite PEM wherein a dispersed conductive organic phase preferentially aligned in the transport direction controls proton transport, and a continuous hydrophobic phase provides mechanical durability to the PEM. The hypothesis that was driving this research was that one might expect better dispersion, higher surface to volume ratio and improved proton conductivity of a composite membrane if the dispersed particles were nanometer in size and had high ion exchange capacity (IEC, = [mmol sulfonic acid]/gram of polymer). In view of this, considerable efforts were employed in the synthesis of high IEC organic nanoparticles and fabrication of a composite membrane with controlled microstructure. High IEC, ~ 4.5 meq/g (in acid form, theoretical limit is 5.4 meq/g) nanoparticles were achieved by emulsion copolymerization of a quaternary alkyl ammonium (QAA) neutralized-sulfonated styrene (QAA-SS), styrene, and divinylbenzene (DVB). The effects of varying the counterion of the sulfonated styrene (SS) monomer (alkali metal and QAA cations), SS concentration, and the addition of a crosslinking agent (DVB) on the ability to stabilize the nanoparticles to higher IECs were assessed. The nanoparticles were ion exchanged to acid form. The extent of ion

  4. Investigation of the doping efficiency of poly(styrene sulfonic acid) in poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) dispersions by capillary electrophoresis.

    PubMed

    Diah, Anang W M; Quirino, Joselito P; Belcher, Warwick; Holdsworth, Clovia I

    2014-07-01

    CE can efficiently separate poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT/PSS) complexes and free PSS in dispersions and can be used to estimate the degree of PSS doping. We investigated the doping efficiency of PSS on PEDOT in dispersions using CE and its effect on the conductivity of the resulting PEDOT/PSS films. Results of this study indicate that dispersions containing 1:2.5-3 EDOT:PSS feed ratio (by weight) exhibiting 72-73% PSS doping generate highly processable and highly conductive films. Conductivity can be optimized by limiting the time of reaction to 12 h. At this point of the reaction, the PEDOT/PSS segments, appearing as broad band in the electropherogram, could still exist in an extended coil conformation favoring charge transport resulting in high conductivity. Above a threshold PEDOT length formed at reaction times longer than 12 h, the PEDOT/PSS complex, appearing as spikes in the electropherogram, most likely have undergone a conformational change to coiled core-shell structure restricting charge transport resulting in low conductivity. The optimal conductivity (5.2 S/cm) of films from dispersions synthesized for 12 h is significantly higher than those from its commercial equivalent Clevios P and other reported values obtained under similar conditions without the addition of codopants. PMID:24782292

  5. Polymer electrolytes based on sulfonated polysulfone for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Lufrano, F.; Baglio, V.; Staiti, P.; Arico', A. S.; Antonucci, V.

    This paper reports the development and characterization of sulfonated polysulfone (SPSf) polymer electrolytes for direct methanol fuel cells. The synthesis of sulfonated polysulfone was performed by a post sulfonation method using trimethyl silyl chlorosulfonate as a mild sulfonating agent. Bare polysulfone membranes were prepared with two different sulfonation levels (60%, SPSf-60 and 70%, SPSf-70), whereas, a composite membrane of SPSf-60 was prepared with 5 wt% silica filler. These membranes were investigated in direct methanol fuel cells (DMFCs) operating at low (30-40 °C) and high temperatures (100-120 °C). DMFC power densities were about 140 mW cm -2 at 100 °C with the bare SPSf-60 membrane and 180 mW cm -2 at 120 °C with the SPSf-60-SiO2 composite membrane. The best performance achieved at ambient temperature using a membrane with high degree of sulfonation (70%, SPSf-70) was 20 mW cm -2 at atmospheric pressure. This makes the polysulfone-based DMFC suitable for application in portable devices.

  6. Quantitative determination of fluorotelomer sulfonates in groundwater by LC MS/MS.

    PubMed

    Schultz, Melissa M; Barofsky, Douglas F; Field, Jennifer A

    2004-03-15

    Aqueous film-forming foams (AFFF) are complex mixtures containing fluorocarbon- and hydrocarbon-based surfactants that are used to fight hydrocarbon-fueled fires. The military is the largest consumer of AFFF in the United States, and fire-training activities conducted at military bases have led to groundwater contamination by unspent fuels and AFFF chemicals. A direct-injection, liquid-chromatography tandem mass spectrometry (LC MS/MS) method was developed to quantify a suite of fluorotelomer sulfonate surfactants in groundwater collected from military bases where fire-training activities were conducted. The 4:2, 6:2, and 8:2 fluorotelomer sulfonates were detected and quantified in groundwater from two of the three military bases. The total fluorotelomer sulfonate concentrations observed at Wurtsmith AFB, MI, and Tyndall AFB, FL, ranged respectively from below quantitation (< or = 0.60) to 182 microg/L and from 1100 to 14,600 microg/L. Analyses of a fluorotelomer-based AFFF concentrate by negative ion fast atom bombardment/mass spectrometry and LC MS/MS analyses indicate that the AFFF concentrate contains only a small amount of fluorotelomer sulfonates and that fluoroalkylthioamido sulfonates are the main anionic fluorosurfactant in the mixtures. More research is needed to determine the fate of fluoroalkylthioamido sulfonates in the environment.

  7. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination from textiles.

    PubMed

    Supreeyasunthorn, Phenpimuk; Boontanon, Suwanna K; Boontanon, Narin

    2016-01-01

    The goals of this study were to determine the concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in textiles and to determine PFOS and PFOA contamination in textile washing water. Quantification analysis was performed by high performance liquid chromatography coupled with tandem mass spectrometry. Analysis of 32 textile samples by methanol extraction revealed that the average concentrations of PFOS and PFOA were 0.18 µg m(-2) (0.02 to 0.61 µg m(-2)) and 2.74 µg m(-2) (0.31 to 14.14 µg m(-2)), respectively. Although the average concentration of PFOS found in textile samples was below European Union (EU) Commission regulations (<1 µg m(-2)), the average concentration of PFOA was 2.74 µg m(-2), and 68.75% of textile samples had PFOA concentrations exceeding 1 µg m(-2). Thus, based on these results, the concentration of PFOA in products should also be regulated. Experiments on PFOS and PFOA leaching into washing water were conducted. The maximum concentrations of PFOS and PFOA were measured after the first washing; the concentrations gradually decreased with each subsequent washing. PFOS and PFOA migrated from textiles and were released into the environment, with disappearance percentages of 29.8% for PFOS and 99% for PFOA. The data presented in this study showed that textiles could be a significant direct and indirect source of PFOS and PFOA exposure for both humans and the environment.

  8. Phthalocyanines And Their Sulfonated Derivatives As Photosensitizers In Photodynamic Therapy.

    NASA Astrophysics Data System (ADS)

    Riesz, Peter; Krishna, C. Murali

    1988-02-01

    Photodynamic therapy (PDT) of human tumors with hematoporphyrin derivative (HpD) has achieved encouraging results. However, HpD is a complex mixture whose composition varies in different preparations and with time of storage. The future promise of PDT for cancer treatment depends on the development of new chemically defined sensitizers which absorb more strongly than HpD in the 600-800 nm region. A shift to higher wavelengths is desirable since it allows increased light penetration in human tissues. In vivo, these sensitizers should be non-toxic, localize selectively in tumors and generate cytotoxic species upon illumination with a high quantum yield. These damaging species may be singlet oxygen (1O2) produced by the transfer of energy from the triplet state of the sensitizer to oxygen (Type II) or superoxide anion radicals formed by electron transfer to oxygen or substrate radicals generated by electron or hydrogen transfer directly from the sensitizer (Type I). The recent work of several groups indicating that phthalocyanines and their water soluble derivatives are promising candidates for PDT is reviewed. The photophysics, photochemistry, photosensitized killing of cultured mammalian cells and the use for in vivo photodynamic therapy of phthalocyanines is outlined. Our studies of the post-illumination photohemolysis of human red blood cells as a model system for membrane photomodification sensitized by phthalocyanine sulfonates are consistent with the predominant role of 1O2 as the damaging species.

  9. Determination of perfluoroalkyl carboxylic, sulfonic, and phosphonic acids in food.

    PubMed

    Ullah, Shahid; Alsberg, Tomas; Vestergren, Robin; Berger, Urs

    2012-11-01

    A sensitive and accurate method was developed and validated for simultaneous analysis of perfluoroalkyl carboxylic acids, sulfonic acids, and phosphonic acids (PFPAs) at low picograms per gram concentrations in a variety of food matrices. The method employed extraction with acetonitrile/water and cleanup on a mixed-mode co-polymeric sorbent (C8 + quaternary amine) using solid-phase extraction. High-performance liquid chromatographic separation was achieved on a C18 column using a mobile phase gradient containing 5 mM 1-methyl piperidine for optimal chromatographic resolution of PFPAs. A quadrupole time-of-flight high-resolution mass spectrometer operating in negative ion mode was used as detector. Method detection limits were in the range of 0.002 to 0.02 ng g(-1) for all analytes. Sample preparation (extraction and cleanup) recoveries at a spiking level of 0.1 ng g(-1) to a baby food composite were in the range of 59 to 98 %. A strong matrix effect was observed in the analysis of PFPAs in food extracts, which was tentatively assigned to sorption of PFPAs to the injection vial in the solvent-based calibration standard. The method was successfully applied to a range of different food matrices including duplicate diet samples, vegetables, meat, and fish samples.

  10. Fate of linear alkylbenzene sulfonate in the Mississippi River

    USGS Publications Warehouse

    Tabor, C.F.; Barber, L.B.

    1996-01-01

    The 2 800-km reach of the Mississippi River between Minneapolis, MN, and New Orleans, LA, was examined for the occurrence and fate of linear alkylbenzene sulfonate (LAS), a common anionic surfactant found in municipal sewage effluents. River water and bottom sediment were sampled in the summer and fall of 1991 and in the spring of 1992. LAS was analyzed using solid- phase extraction/derivatization/gas chromatography/mass spectrometry. LAS was present on all bottom sediments at concentrations ranging from 0.01 to 20 mg/kg and was identified in 21% of the water samples at concentrations ranging from 0.1 to 28.2 ??g/L. The results indicate that LAS is a ubiquitous contaminant on Mississippi River bottom sediments and that dissolved LAS is present mainly downstream from the sewage outfalls of major cities. The removal of the higher LAS homologs and external isomers indicates that sorption and biodegradation are the principal processes affecting dissolved LAS. Sorbed LAS appears to degrade slowly.

  11. Amitriptyline, clomipramine, and doxepin adsorption onto sodium polystyrene sulfonate

    PubMed Central

    2014-01-01

    Purpose of the study Comparative in vitro studies were carried out to determine the adsorption characteristics of 3 drugs on activated charcoal (AC) and sodium polystyrene sulfonate (SPS). Activated charcoal (AC) has been long used as gastric decontamination agent for tricyclic antidepressants (TCA). Methods Solutions containing drugs (amitriptyline, clomipramine, or doxepin) and variable amount of AC or SPS were incubated for 30 minutes. Results At pH 1.2 the adsorbent: drug mass ratio varied from 2 : 1 to 40 : 1 for AC, and from 0.4 : 1 to 8 : 1 for SPS. UV–VIS spectrophotometer was used for the determination of free drug concentrations. The qmax of amitriptyline was 0.055 mg/mg AC and 0.574 mg/mg SPS, qmax of clomipramine was 0.053 mg/mg AC and 0.572 mg/mg SPS, and qmax of doxepin was 0.045 mg/mg AC and 0.556 mg/mg SPS. The results of adsorption experiments with SPS revealed higher values for the qmax parameters in comparison with AC. Conclusion In vitro gastric decontamination experiments for antidepressant amitriptyline, clomipramine, and doxepin showed that SPS has higher qmax values than the corresponding experiments with AC. Therefore, we suggest SPS is a better gastric decontaminating agent for the management of acute TCA intoxication. PMID:24450391

  12. Partitioning characteristics of perfluorooctane sulfonate between water and foods.

    PubMed

    Xiao, Feng; Simcik, Matt F; Gulliver, John S

    2012-01-01

    As a persistent, bioaccumulative, and toxic organic pollutant, perfluorooctane sulfonate (PFOS) has been found ubiquitously in the environment, including in tap water. For the first time, we studied PFOS sorption from water to foods (nine commonly consumed vegetables, three meats, and cereals) at two temperatures to estimate the daily intake of PFOS attributable to cooking and food preparation. The values of the food water-distribution coefficient (KF/W, l/kg) of PFOS ranged from 7 to 19 l/kg for most vegetables and from 19 to 38 l/kg for meats. Celery exhibited the highest affinity toward PFOS (KF/W=39.8±3.4 l/kg), whereas onions showed the lowest affinity toward PFOS (KF/W=1.1±0.4 l/kg). Adding table salt (sodium chloride) greatly increased PFOS sorption in most foods, except for celery and meats. The results indicate that human exposure to PFOS could result from the sorption of PFOS from water to food during food preparation, especially when using table salt. The average daily intake of PFOS through this route was estimated. Furthermore, raw and unprocessed foods (vegetables, meats, and cereals) bought from farmers' markets and grocery stores were basically free of PFOS and other long-chain perfluoroalkyl acids.

  13. Partitioning characteristics of perfluorooctane sulfonate between water and foods.

    PubMed

    Xiao, Feng; Simcik, Matt F; Gulliver, John S

    2012-01-01

    As a persistent, bioaccumulative, and toxic organic pollutant, perfluorooctane sulfonate (PFOS) has been found ubiquitously in the environment, including in tap water. For the first time, we studied PFOS sorption from water to foods (nine commonly consumed vegetables, three meats, and cereals) at two temperatures to estimate the daily intake of PFOS attributable to cooking and food preparation. The values of the food water-distribution coefficient (KF/W, l/kg) of PFOS ranged from 7 to 19 l/kg for most vegetables and from 19 to 38 l/kg for meats. Celery exhibited the highest affinity toward PFOS (KF/W=39.8±3.4 l/kg), whereas onions showed the lowest affinity toward PFOS (KF/W=1.1±0.4 l/kg). Adding table salt (sodium chloride) greatly increased PFOS sorption in most foods, except for celery and meats. The results indicate that human exposure to PFOS could result from the sorption of PFOS from water to food during food preparation, especially when using table salt. The average daily intake of PFOS through this route was estimated. Furthermore, raw and unprocessed foods (vegetables, meats, and cereals) bought from farmers' markets and grocery stores were basically free of PFOS and other long-chain perfluoroalkyl acids. PMID:21597984

  14. Using silica nanoparticles for modifying sulfonated poly(phthalazinone ether ketone) membrane for direct methanol fuel cell: A significant improvement on cell performance

    NASA Astrophysics Data System (ADS)

    Su, Yu-Huei; Liu, Ying-Ling; Sun, Yi-Ming; Lai, Juin-Yih; Guiver, Michael D.; Gao, Yan

    Sulfonated poly(phthalazinone ether ketone) (sPPEK) with a degree of sulfonation of 1.23 was mixed with silica nanoparticles to form hybrid materials for using as proton exchange membranes. The nanoparticles were found homogeneously dispersed in the polymer matrix and a high 30 phr (parts per hundred resin) loading of silica nanoparticles can be achieved. The hybrid membranes exhibited improved swelling behavior, thermal stability, and mechanical properties. The methanol crossover behavior of the membrane was also depressed such that these membranes are suitable for a high methanol concentration in feed (3 M) in cell test. The membrane with 5 phr silica nanoparticles showed an open cell potential of 0.6 V and an optimum power density of 52.9 mW cm -2 at a current density of 264.6 mA cm -2, which is better than the performance of the pristine sPPEK membrane and Nafion ® 117.

  15. Recycle waste salt as reagent: a one-pot substitution/Krapcho reaction sequence to α-fluorinated esters and sulfones.

    PubMed

    Zhu, Feng; Xu, Peng-Wei; Zhou, Feng; Wang, Cui-Hong; Zhou, Jian

    2015-02-20

    A "one-pot" tandem substitution/Krapcho reaction is reported for the facile synthesis of α-fluorinated esters and sulfones, which utilizes the byproduct salt formed in the substitution step as an indispensible reagent to facilitate the Krapcho reaction step. This represents the first sustainable tandem reaction that internally recycles the waste salt formed in the upstream step as the reagent for the downstream step.

  16. Ag (I)-based 2D metal frameworks with helical structures decorated by the homochiral camphor-10-sulfonic acid

    NASA Astrophysics Data System (ADS)

    Guo, Peng; Wang, Jing; Wang, Jun; Pan, Daocheng; Xu, Guohai

    2010-12-01

    Two two-dimension homochiral Ag (I) metal frameworks constructed from enantiopure camphor-10-sulfonic acid and hexamethylenetetramine have been synthesized at the room temperature. These two complexes with (6, 3) topology decorated by the homochiral camphor-10-sulfonic acid possess the unique helical structures. The result of Circular Dichroism (CD) spectroscopy confirms that the bulk materials are homochiral and also indicates the handedness of the single crystals can be controlled by the chirality of the camphor-10-sulfonic acid.

  17. Isolation and Characterization of the 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) Radical Cation-Scavenging Reaction Products of Arbutin.

    PubMed

    Tai, Akihiro; Ohno, Asako; Ito, Hideyuki

    2016-09-28

    Arbutin, a glucoside of hydroquinone, has shown strong 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation-scavenging activity, especially in reaction stoichiometry. This study investigated the reaction mechanism of arbutin against ABTS radical cation that caused high stoichiometry of arbutin in an ABTS radical cation-scavenging assay. HPLC analysis of the reaction mixture of arbutin and ABTS radical cation indicated the existence of two reaction products. The two reaction products were purified and identified to be a covalent adduct of arbutin with an ABTS degradation fragment and 3-ethyl-6-sulfonate benzothiazolone. A time-course study of the radical-scavenging reactions of arbutin and the two reaction products suggested that one molecule of arbutin scavenges three ABTS radical cation molecules to generate an arbutin-ABTS fragment adduct as a final reaction product. The results suggest that one molecule of arbutin reduced two ABTS radical cation molecules to ABTS and then cleaved the third ABTS radical cation molecule to generate two products, an arbutin-ABTS fragment adduct and 3-ethyl-6-sulfonate benzothiazolone.

  18. Isolation and Characterization of the 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) Radical Cation-Scavenging Reaction Products of Arbutin.

    PubMed

    Tai, Akihiro; Ohno, Asako; Ito, Hideyuki

    2016-09-28

    Arbutin, a glucoside of hydroquinone, has shown strong 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation-scavenging activity, especially in reaction stoichiometry. This study investigated the reaction mechanism of arbutin against ABTS radical cation that caused high stoichiometry of arbutin in an ABTS radical cation-scavenging assay. HPLC analysis of the reaction mixture of arbutin and ABTS radical cation indicated the existence of two reaction products. The two reaction products were purified and identified to be a covalent adduct of arbutin with an ABTS degradation fragment and 3-ethyl-6-sulfonate benzothiazolone. A time-course study of the radical-scavenging reactions of arbutin and the two reaction products suggested that one molecule of arbutin scavenges three ABTS radical cation molecules to generate an arbutin-ABTS fragment adduct as a final reaction product. The results suggest that one molecule of arbutin reduced two ABTS radical cation molecules to ABTS and then cleaved the third ABTS radical cation molecule to generate two products, an arbutin-ABTS fragment adduct and 3-ethyl-6-sulfonate benzothiazolone. PMID:27607833

  19. Friedel–Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery

    PubMed Central

    Merle, Géraldine; Ioana, Filipoi Carmen; Demco, Dan Eugen; Saakes, Michel; Hosseiny, Seyed Schwan

    2014-01-01

    Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel–Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion. PMID:24957118

  20. Chemical and microbial community analysis during aerobic biostimulation assays of non-sulfonated alkyl-benzene-contaminated groundwater.

    PubMed

    Martínez-Pascual, Eulàlia; Jiménez, Nuria; Vidal-Gavilan, Georgina; Viñas, Marc; Solanas, A M

    2010-10-01

    A chemical and microbial characterization of lab-scale biostimulation assays with groundwater samples taken from an industrial site in which the aquifer had been contaminated by linear non-sulfonate alkyl benzenes (LABs) was carried out for further field-scale bioremediation purposes. Two lab-scale biodegradability assays were performed, one with a previously obtained gas-oil-degrading consortium and another with the native groundwater flora. Results for the characterization of the groundwater microbial population of the site revealed the presence of an important LAB-degrading microbial population with a strong degrading capacity. Among the microorganisms identified at the site, the detection of Parvibaculum lavamentivorans, which have been described in other studies as alkyl benzene sulfonates degraders, is worth mentioning. Incubation of P. lavamentivorans DSMZ13023 with LABs as reported in this study shows for the first time the metabolic capacity of this strain to degrade such compounds. Results from the biodegradation assays in this study showed that the indigenous microbial population had a higher degrading capacity than the gas-oil-degrading consortium, indicating the strong ability of the native community to adapt to the presence of LABs. The addition of inorganic nutrients significantly improved the aerobic biodegradation rate, achieving levels of biodegradation close to 90%. The results of this study show the potential effectiveness of oxygen and nutrients as in situ biostimulation agents as well as the existence of a complex microbial community that encompasses well-known hydrocarbon- and LAS-degrading microbial populations in the aquifer studied.

  1. Friedel-Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery.

    PubMed

    Merle, Géraldine; Ioana, Filipoi Carmen; Demco, Dan Eugen; Saakes, Michel; Hosseiny, Seyed Schwan

    2013-12-30

    Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel-Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion.

  2. Iron-Catalyzed Cross-Coupling of Unactivated, Secondary Alkyl Thio Ethers and Sulfones with Aryl Grignard Reagents

    PubMed Central

    Denmark, Scott E.; Cresswell, Alexander J.

    2013-01-01

    The first systematic investigation of unactivated aliphatic sulfur compounds as electrophiles in transition metal-catalyzed cross-coupling are described. Initial studies focused on discerning the structural and electronic features of the organosulfur substrate which enable the challenging oxidative addition to the C(sp3)–S bond. Through extensive optimization efforts, an Fe(acac)3-catalyzed cross-coupling of unactivated alkyl aryl thio ethers with aryl Grignard reagents was realized, in which a nitrogen “directing group” on the S-aryl moiety of the thio ether served a critical role in facilitating the oxidative addition step. In addition, alkyl phenyl sulfones were found to be effective electrophiles in the Fe(acac)3-catalyzed cross-coupling with aryl Grignard reagents. For the latter class of electrophile, a thorough assessment of the various reaction parameters revealed a dramatic enhancement in reaction efficiency with an excess of TMEDA (8.0 equiv). The optimized reaction protocol was used to evaluate the scope of the method with respect to both the organomagnesium nucleophile and sulfone electrophile. PMID:24256193

  3. The Efficacy and Underlying Mechanism of Sulfone Derivatives Containing 1,3,4-oxadiazole on Citrus Canker.

    PubMed

    Li, Pei; Ma, Yuhua; Zhou, Junliang; Luo, Hui; Yan, Jiawen; Mao, Yongya; Wang, Zhuang

    2015-08-04

    The objectives of the current study were to isolate and identify the pathogen responsible for citrus canker and investigate the efficacy of sulfone derivatives containing 1,3,4-oxadiazole moiety on controlling citrus canker caused by Xanthomonas citri subsp. citri (Xcc) under in vitro and field conditions. In an in vitro study, we tested eight sulfone derivatives against Xcc and the results demonstrated that compound 3 exhibited the best antibacterial activity against Xcc, with a half-maximal effective concentration (EC50) value of 1.23 μg/mL, which was even better than those of commercial bactericides Kocide 3000 (58.21 μg/mL) and Thiodiazole copper (77.04 μg/mL), respectively. Meanwhile, under field experiments, compound 3 treatments demonstrated the highest ability to reduce the disease of citrus canker in leaves and fruits in two different places relative to an untreated control as well as the commercial bactericides Kocide 3000 and Thiodiazole copper. Meanwhile, compound 3 could stimulate the increase in peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) activities in the navel orange leaves, causing marked enhancement of plant resistance against citrus canker. Moreover, compound 3 could damage the cell membranes, destruct the biofilm formation, inhibit the production of extracellular polysaccharide (EPS), and affect the cell membrane permeability to restrain the growth of the bacteria.

  4. Imidazolium Sulfonates as Environmental-Friendly Catalytic Systems for the Synthesis of Biologically Active 2-Amino-4H-chromenes: Mechanistic Insights.

    PubMed

    Velasco, Jacinto; Pérez-Mayoral, Elena; Calvino-Casilda, Vanesa; López-Peinado, Antonio J; Bañares, Miguel A; Soriano, Elena

    2015-09-10

    Ionic Liquids (ILs) are valuable reaction media extremely useful in industrial sustainable organic synthesis. We describe here the study on the multicomponent reaction (MCR) between salicylaldehyde (2) and ethyl cyanoacetate (3), catalyzed by imidazolium sulfonates, to form chromenes 1, a class of heterocyclic scaffolds exhibiting relevant biological activity. We have clarified the reaction mechanism by combining the experimental results with computational studies. The results reported herein suggest that both the imidazolium core and the sulfonate anions in the selected ILs are involved in the reaction course acting as hydrogen bond donors and acceptors, respectively. Contrarily to the most widely accepted mechanism through initial Knoevenagel condensation, the most favorable reaction pathway consists of an aldolic reaction between reagents followed by heterocyclization, subsequent dehydration, and, finally, the Michael addition of the second molecule of ethyl cyanoacetate (3) to yield the chromenes 1. PMID:26301460

  5. Advances in membrane materials: desalination membranes based on directly copolymerized disulfonated poly(arylene ether sulfone) random copolymers.

    PubMed

    Xie, Wei; Park, Ho-Bum; Cook, Joseph; Lee, Chang Hyun; Byun, Gwangsu; Freeman, Benny D; McGrath, James E

    2010-01-01

    The water and salt transport properties of chlorine tolerant disulfonated poly(arylene ether sulfone) (BPS) copolymers have been characterized. Cast BPS membranes of both salt form and acid form with sulfonation levels from 20% to 40% were investigated. Water permeability of BPS films increases more than one order of magnitude as sulfonation level increases from 20% to 40%, while the salt permeability of the corresponding membranes increases two orders of magnitude. Moderate salt rejection (98.2%) was achieved by a BPS salt form membrane with a sulfonation level of 20%.

  6. Which one is preferred: Myers-Saito cyclization of ene-yne-allene or Garratt-Braverman cyclization of conjugated bisallenic sulfone? A theoretical and experimental study.

    PubMed

    Basak, Amit; Das, Sanket; Mallick, Dibyendu; Jemmis, Eluvathingal D

    2009-11-01

    A competitive scenario between Myers-Saito (MS) and Garratt-Braverman (GB) cyclization has been created in a molecule. High-level computations indicate a preference for GB over MS cyclization. The activation energies for the rate-determining steps of the GB and MS cyclizations were found to be the same (24.4 kcal/mol) at the B3LYP/6-31G* level of theory; thus, from the kinetic point of view, both reactions are feasible. However, the main biradical intermediate GB2 of the GB reaction is 6.2 kcal/mol lower in energy than the biradical MS2, which is the main intermediate of MS reaction, so GB cyclization is thermodynamically favored over MS cyclization. To verify the prediction by computational techniques, bisenediynyl sulfones 1-4 and bisenediynyl sulfoxide 17 were synthesized. Under basic conditions, these molecules isomerized to a system possessing both the ene-yne-allene and the bisallenic sulfone. The isolation of only one product, identified as the corresponding naphthalene- or benzene-fused sulfone 8-11, indicated the occurrence of GB cyclization as the sole reaction pathway. No product corresponding to the MS cyclization pathway could be isolated. Though the theoretical prediction showed a preference for the GB pathway over the MS pathway, the exclusive preference for GB over MS cyclization is very striking. Further analysis showed that the intramolecular self-quenching nature of the GB pathway may play an important role in the complete preference for this reaction. Apart from the mechanistic studies, these sulfones showed DNA cleavage activity that had an inverse relation with the reactivity order. Our findings are important for the design of artificial DNA-cleaving agents.

  7. [Studies for analyzing restricted ingredients such as phenylbenzoimidazole sulfonic acid].

    PubMed

    Tokunaga, Hiroshi; Mori, Kenichiro; Onuki, Nahomi; Nosaka, Tomio; Doi, Kayo; Sakaguchi, Hiroshi; Fujii, Makiko; Takano, Katuhiro; Hayashi, Masato; Yoshizawa, Kenichi; Shimamura, Kimio; Sato, Nobuo

    2006-01-01

    Phenylbenzoimidazol sulfonic acid (PBS) is a kind of sunscreens in cosmetics and is nominated as the restricted ingredients in cosmetics in Japanese Pharmaceutical Affairs Act. So the analytical method for PBS was investigated by HPLC. 1.0 g of the lotions with 1.0% PBS was exactly weighed, put into a 50-mL volumetric flask. Water was added to make exactly 50 mL and this mixture was used as the sample solution. On the other hand, 1.0 g of the creams with 1.0% PBS was exactly weighed, put into a beaker. After adding 1 mL of tetrahydrofuran and dissolving the cream, that mixture was transferred to a 50-mL volumetric flask. And then the beaker was rinsed with 1 mL of tetrahydrofuran and the rinsed solution was put together into the volumetric flask. After adding water to the volumetric flask to make exactly 50 mL, this mixture was used as the sample solution. If necessary, the mixture was filtrated with a membrane filter (0.45 microm). 5.0 mL of the sample solution was pipetted and put into a 200-mL volumetric flask. After adding water to make exactly 200 mL, 20 microL of this solution was analyzed by HPLC using the ODS column (CAPCELL PAK C18 column, 4.6 mm i.d. x 250 mm), the mixture of 40 mmol/L acetic buffer (pH 3.4) and acetonitrile (3:1) with 0.8 mmol/L dodecyltrimethyl ammonium bromide and the detection wavelength of 305 nm. The working curve from 0.5 to 20.0 microg/mL showed a linear line between the concentrations of PBS and the peak areas. There was no interference of peak of PBS from the lotion and cream.

  8. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films.

    PubMed

    Zorn, Gilad; Migonney, Véronique; Castner, David G

    2014-09-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm(2).

  9. A sulfonic-azobenzene-grafted silica amphiphilic material: a versatile stationary phase for mixed-mode chromatography.

    PubMed

    Qiu, Hongdeng; Zhang, Mingliang; Gu, Tongnian; Takafuji, Makoto; Ihara, Hirotaka

    2013-12-23

    A novel sulfonic-azobenzene-functionalized amphiphilic silica material was synthesized through the preparation of a new sulfonic azobenzene monomer and its grafting on mercaptopropyl-modified silica by a surface-initiated radical chain-transfer reaction. The synthesis was confirmed by infrared spectra, elemental analysis, and thermogravimetric analysis. This new material was successfully applied as a new kind of mixed-mode stationary phase in liquid chromatography. This allows an exceptionally flexible adjustment of retention and selectivity by tuning the experimental conditions. The distinct separation mechanisms were outlined by selected examples of chromatographic separations in the different modes. In reversed-phase liquid chromatography, this new stationary phase presented specific chromatographic performance when evaluated using a Tanaka test mixture. Seven dinitro aromatic isomers, four steroids, and seven flavonoids were separated successfully in simple reversed-phase mode. This stationary phase can also be used in hydrophilic interaction chromatography because of the existing polar functional groups; for this, nucleosides and their bases were used as a test mixture. Interestingly, the same nucleosides and bases can also be separated in per aqueous liquid chromatography using the same stationary phase. Three ginsenosides including Rg1, Re, and Rb1 were successfully separated in hydrophilic mode. There is the potential for more applications to benefit from this useful column. PMID:24353082

  10. Degradation of poly(ether sulfone)/polyvinylpyrrolidone membranes by sodium hypochlorite: insight from advanced electrokinetic characterizations.

    PubMed

    Hanafi, Yamina; Szymczyk, Anthony; Rabiller-Baudry, Murielle; Baddari, Kamel

    2014-11-18

    Poly(ether sulfone) (PES)/polyvinylpyrrolidone (PVP) membranes are widely used in various industrial fields such as drinking water production and in the dairy industry. However, the use of oxidants to sanitize the processing equipment is known to impair the integrity and lifespan of polymer membranes. In this work we showed how thorough electrokinetic measurements can provide essential information regarding the mechanism of degradation of PES/PVP membranes by sodium hypochlorite. Tangential streaming current measurements were performed with ultrafiltration and nanofiltration PES/PVP membranes for various aging times. The electrokinetic characterization of membranes was complemented by FTIR-ATR spectroscopy. Results confirmed that sodium hypochlorite induces the degradation of both PES and PVP. This latter is easily oxidized by sodium hypochlorite, which leads to an increase in the negative charge density of the membrane due to the formation of carboxylic acid groups. The PVP was also found to be partly released from the membrane with aging time. Thanks to the advanced electrokinetic characterization implemented in this work it was possible for the first time to demonstrate that two different mechanisms are involved in the degradation of PES. Phenol groups were first formed as a result of the oxidation of PES aromatic rings by substitution of hydrogen by hydroxyl radicals. For more severe aging conditions, this membrane degradation mechanism was followed by the formation of sulfonic acid functions, thus indicating a second degradation process through scission of PES chains. PMID:25365117

  11. Simultaneous determination of ofloxacin and gatifloxacin on cysteic acid modified electrode in the presence of sodium dodecyl benzene sulfonate.

    PubMed

    Zhang, Fenfen; Gu, Shuqing; Ding, Yaping; Li, Li; Liu, Xiao

    2013-02-01

    A novel cysteic acid modified carbon paste electrode (cysteic acid/CPE) based on electrochemical oxidation of L-cysteine was developed to simultaneously determine ofloxacin and gatifloxacin in the presence of sodium dodecyl benzene sulfonate (SDBS). Fourier transform infrared spectra (FTIR) indicated that L-cysteine was oxidated to cysteic acid. Electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) indicated that cysteic acid was successfully modified on electrode. The large peak separation (116 mV) between ofloxacin and gatifloxacin was obtained on cysteic acid/CPE while only one oxidation peak was found on bare electrode. And the peak currents increased 5 times compared to bare electrode. Moreover, the current could be further enhanced in the presence of an anionic surfactant, sodium dodecyl benzene sulfonate. The differential pulse voltammograms (DPV) exhibited that the oxidation peak currents were linearly proportional to their concentrations in the range of 0.06-10 μM for ofloxacin and 0.02-200 μM for gatifloxacin, and the detection limits of ofloxacin and gatifloxacin were 0.02 μM and 0.01 μM (S/N=3), respectively. This proposed method was successfully applied to determine ofloxacin and gatifloxacin in pharmaceutical formulations and human serum samples.

  12. Preparation of Pt/polypyrrole-para toluene sulfonate hydrogen peroxide sensitive electrode for the utilizing as a biosensor.

    PubMed

    Çete, Servet; Bal, Özgür

    2013-12-01

    A film electrode with electropolymerization of pyrrole (Py) and para-toluene sulfonate (pTS) as a anionic dopant is prepared and its sensitivity to hydrogen peroxide is investigated. The polypyrrole is deposited on a 0.5 cm(2) Pt plate an electrochemically prepared pTS ion-doped polypyrrole film by scanning the electrode potential between - 0.8 and + 0.8 V at a scan rate of 20 mV/s. The electrode's sensitivity to hydrogen peroxide is investigated at room temperature using 0.1 M phosphate buffer at pH 7.5. The working potential is found as a 0.3 V. The concentrations of pyrrole and pTS are 50mM M and 25 mM. Polypyrrole was coated on the electrode surface within 10 cycles. İmmobilization of glucose oxidase carried out on Pt/polypyrrole-para toluene sulfonate (Pt/PPy-pTS) film by cross-linking with glutaraldehyde. The morphology of electrodes was characterized by SEM and AFM. Moreover, contact angle measurements were made with 1 μL water of polymer film and enzyme electrode. It has shown that enzyme electrode is very sensitive against to glucose.

  13. Degradation of poly(ether sulfone)/polyvinylpyrrolidone membranes by sodium hypochlorite: insight from advanced electrokinetic characterizations.

    PubMed

    Hanafi, Yamina; Szymczyk, Anthony; Rabiller-Baudry, Murielle; Baddari, Kamel

    2014-11-18

    Poly(ether sulfone) (PES)/polyvinylpyrrolidone (PVP) membranes are widely used in various industrial fields such as drinking water production and in the dairy industry. However, the use of oxidants to sanitize the processing equipment is known to impair the integrity and lifespan of polymer membranes. In this work we showed how thorough electrokinetic measurements can provide essential information regarding the mechanism of degradation of PES/PVP membranes by sodium hypochlorite. Tangential streaming current measurements were performed with ultrafiltration and nanofiltration PES/PVP membranes for various aging times. The electrokinetic characterization of membranes was complemented by FTIR-ATR spectroscopy. Results confirmed that sodium hypochlorite induces the degradation of both PES and PVP. This latter is easily oxidized by sodium hypochlorite, which leads to an increase in the negative charge density of the membrane due to the formation of carboxylic acid groups. The PVP was also found to be partly released from the membrane with aging time. Thanks to the advanced electrokinetic characterization implemented in this work it was possible for the first time to demonstrate that two different mechanisms are involved in the degradation of PES. Phenol groups were first formed as a result of the oxidation of PES aromatic rings by substitution of hydrogen by hydroxyl radicals. For more severe aging conditions, this membrane degradation mechanism was followed by the formation of sulfonic acid functions, thus indicating a second degradation process through scission of PES chains.

  14. Quantum mechanics-based scoring rationalizes the irreversible inactivation of parasitic Schistosoma mansoni cysteine peptidase by vinyl sulfone inhibitors.

    PubMed

    Fanfrlík, Jindřich; Brahmkshatriya, Pathik S; Řezáč, Jan; Jílková, Adéla; Horn, Martin; Mareš, Michael; Hobza, Pavel; Lepšík, Martin

    2013-12-01

    The quantum mechanics (QM)-based scoring function that we previously developed for the description of noncovalent binding in protein-ligand complexes has been modified and extended to treat covalent binding of inhibitory ligands. The enhancements are (i) the description of the covalent bond breakage and formation using hybrid QM/semiempirical QM (QM/SQM) restrained optimizations and (ii) the addition of the new ΔG(cov)' term to the noncovalent score, describing the "free" energy difference between the covalent and noncovalent complexes. This enhanced QM-based scoring function is applied to a series of 20 vinyl sulfone-based inhibitory compounds inactivating the cysteine peptidase cathepsin B1 of the Schistosoma mansoni parasite (SmCB1). The available X-ray structure of the SmCB1 in complex with a potent vinyl sulfone inhibitor K11017 is used as a template to build the other covalently bound complexes and to model the derived noncovalent complexes. We present the correlation of the covalent score and its constituents with the experimental binding data. Four outliers are identified. They contain bulky R1' substituents structurally divergent from the template, which might induce larger protein rearrangements than could be accurately modeled. In summary, we propose a new computational approach and an optimal protocol for the rapid evaluation and prospective design of covalent inhibitors with a conserved binding mode. PMID:24195769

  15. Separation and fragmentation study of isocoproporphyrin derivatives by UHPLC-ESI-exact mass MS/MS and identification of a new isocoproporphyrin sulfonic acid metabolite.

    PubMed

    Benton, Christopher M; Lim, Chang Kee; Moniz, Caje; Baxter, Sinéad L; Jones, Donald J L

    2014-01-01

    Isocoproporphyrin and its derivatives are commonly used as biomarkers of porphyria cutanea tarda, heavy metal toxicity and hexachlorobenzene (HCB) intoxication in humans and animals. However, most are isobaric with other porphyrins and reference materials are unavailable commercially. The structural characterisation of these porphyrins is important but very little data is available. We report here the separation and characterisation of isocoproporphyrin, deethylisocoproporphyrin, hydroxyisocoproporphyrin and ketoisocoproporphyrin, isolated in the faeces of rats fed with a diet containing HCB, by ultra high performance liquid chromatography-exact mass tandem mass spectrometry (UHPLC-MS/MS). Furthermore, we report the identification and characterisation of a previously unreported porphyrin metabolite, isocoproporphyrin sulfonic acid isolated in the rat faeces. The measured mass-to-charge ratio (m/z) of the precursor ion was m/z 735.2338, corresponding to a molecular formula of C36H39N4O11S with an error of 0.3 ppm from the calculated m/z 735.2336. The MS/MS data was consistent with an isocoproporphyrin sulfonic acid structure, derived from dehydroisocoproporphyrinogen by sulfonation of the vinyl group. The metabolite was present in a greater abundance than other isocoproporphyrin derivatives and may be a more useful biomarker for HCB intoxication.

  16. Synthesis Of [2h, 13c]M [2h2m 13c], And [2h3,, 13c] Methyl Aryl Sulfones And Sulfoxides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.; Schmidt, Jurgen G.

    2004-07-20

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfones and [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfoxides, wherein the .sup.13 C methyl group attached to the sulfur of the sulfone or sulfoxide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing methyl aryl sulfones and methyl aryl sulfoxides.

  17. Crystal structures of three N-(aryl­sulfon­yl)-4-fluoro­benzamides

    PubMed Central

    Suchetan, P. A.; Naveen, S.; Lokanath, N. K.; Srivishnu, K. S.; Supriya, G. M.; Lakshmikantha, H. N.

    2016-01-01

    The crystal structures of three N-aryl­sulfonyl-4-fluoro­benzamides, namely 4-fluoro-N-(2-methyl­phenyl­sulfon­yl)benzamide, C14H12FNO3S, (I), N-(2-chloro­phenyl­sulfon­yl)-4-fluorobenzamide, C13H9ClFNO3S, (II), and N-(4-chloro­phenyl­sulfon­yl)-4-fluoro­benzamide monohydrate, C13H9ClFNO3S·H2O, (III), are described and compared with related structures. The asymmetric unit of (I) contains two independent mol­ecules (A and B), while that of (II) contains just one mol­ecule, and that of (III) contains a mol­ecule of water in addition to one main mol­ecule. The dihedral angle between the benzene rings is 82.83 (11)° in mol­ecule A and 85.01 (10)° in mol­ecule B of (I), compared to 89.91 (10)° in (II) and 81.82 (11)° in (III). The crystal structure of (I) features strong N—H⋯O hydrogen bonds between the A and B mol­ecules, resulting in an R 4 4(16) tetra­meric unit. These tetra­meric units are connected into sheets in the bc plane by various C—H⋯O inter­actions, and adjacent sheets are further inter­linked via C—H⋯πar­yl inter­actions, forming a three-dimensional architecture. The crystal structure is further stabilized by πar­yl–πar­yl and S=O⋯πar­yl inter­actions. In the crystal of (II), mol­ecules are connected into R 2 2(8) and R 2 2(14) dimers via N—H⋯O hydrogen bonds and C—H⋯O inter­actions, respectively; the dimers are further inter­connected via a weak C=O⋯πar­yl inter­action, leading to the formation of chains along [1-10]. In the crystal of (III), N—H⋯O and O—H⋯O hydrogen bonds involving both the main mol­ecule and the solvent water mol­ecule results in the formation of sheets parallel to the bc plane. The sheets are further connected by C—H⋯O inter­actions and weak C—Cl⋯πar­yl, C—F⋯πar­yl and S=O⋯πar­yl inter­actions, forming a three-dimensional architecture. PMID:27375892

  18. Enhanced osteoblast-like cell adhesion and proliferation using sulfonate-bearing polymeric scaffolds.

    PubMed

    Chaterji, Somali; Gemeinhart, Richard A

    2007-12-15

    Orthopedic malfunction, degeneration, or damage remains a serious healthcare issue despite advances in medical technology. Proactive extracellular matrix (ECM)-mimetic scaffolds are being researched to orchestrate the activation of diverse osteogenic signaling cascades, facilitating osteointegration. We hypothesized that sulfonated functionalities incorporated into synthetic hydrogels would simulate anionic, sulfate-bearing proteoglycans, abundant in the ECM. Using this rationale, we successfully developed differentially sulfonated hydrogels, polymerizing a range of sulfopropyl acrylate potassium-acrylamide (SPAK-AM) mole ratios as monomer feeds under room temperature conditions. For anchorage-dependent cells, such as osteoblasts, adhesion is a critical prerequisite for subsequent osteointegration and cell specialization. The introduction of the sulfonated monomer, SPAK, resulted in favorable uptake of serum proteins with proportional increase in adhesion and proliferation rates of model cell lines, which included NIH/3T3 fibroblasts, MG-63 osteoblasts, and MC3T3-E1 subclone 4 preosteoblasts. In fact, higher proportions of sulfonate content (pSPAK75, pSPAK100) exhibited comparable or even higher degrees of adhesion and proliferation, relative to commercial grade tissue culture polystyrene in vitro. These results indicate promising potentials of sulfonated ECM-mimetic hydrogels as potential osteogenic tissue engineering scaffolds. PMID:17584889

  19. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    SciTech Connect

    Kim, Yu Seung; Kim, Dae Sik; Robertson, Gilles; Guiver, Michael

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  20. Thyroid disruption effects of environmental level perfluorooctane sulfonates (PFOS) in Xenopus laevis.

    PubMed

    Cheng, Yan; Cui, Yuan; Chen, Hui-ming; Xie, Wen-ping

    2011-11-01

    Perfluorooctane sulfonate (PFOS), one of the emerging persistent organic pollutants (POPs), has caused growing international concern especially related to the potential disruption in the development and function of thyroid system. Xenopus laevis is an amphibian species widely used as a suitable amphibian model for thyroid disruption research. To study the thyroid disruption effects related to PFOS exposure at environmental low levels, X. laevis tadpoles were exposed to 0.1, 1, 10 and 100 μg/l PFOS in water respectively from stage 46/47 to stage 62. The results showed that the time to metamorphosis (presented by forelimb emergence, FLE) did not significantly change with PFOS exposure, but exhibited an increasing trend (except for 10 μg/l exposure). Partial colloid depletion was observed for PFOS exposure, but no significant histological abnormality was observed in treatment groups. In addition, PFOS exposure resulted in up-regulation of thyroid hormone-regulated genes-thyroid receptor beta A (TRβA), basic transcription element-binding protein (BTEB) and type II deiodinase (DI2) mRNA expression, presented as an inverted U-shaped dose response pattern. However, the mRNA expression of type III deiodinase (DI3) remained unaffected compared with the control. These results demonstrated that PFOS might disrupt the thyroid system in X. laevis tadpoles regarding FLE changes and regulation alternation of thyroid hormone-regulated genes. Our study has raised new concerns for possible thyroid disruption of PFOS in amphibians at environmental relevant levels. PMID:21809121

  1. Perfluorooctane sulfonate (PFOS) contamination of fish in urban lakes: a prioritization methodology for lake management.

    PubMed

    Xiao, Feng; Gulliver, John S; Simcik, Matt F

    2013-12-15

    The contamination of urban lakes by anthropogenic pollutants such as perfluorooctane sulfonate (PFOS) is a worldwide environmental problem. Large-scale, long-term monitoring of urban lakes requires careful prioritization of available resources, focusing efforts on potentially impaired lakes. Herein, a database of PFOS concentrations in 304 fish caught from 28 urban lakes was used for development of an urban-lake prioritization framework by means of exploratory data analysis (EDA) with the aid of a geographical information system. The prioritization scheme consists of three main tiers: preliminary classification, carried out by hierarchical cluster analysis; predictor screening, fulfilled by a regression tree method; and model development by means of a neural network. The predictive performance of the newly developed model was assessed using a training/validation splitting method and determined by an external validation set. The application of the model in the U.S. state of Minnesota identified 40 urban lakes that may contain elevated levels of PFOS; these lakes were not previously considered in PFOS monitoring programs. The model results also highlight ongoing industrial/commercial activities as a principal determinant of PFOS pollution in urban lakes, and suggest vehicular traffic as an important source and surface runoff as a primary pollution carrier. In addition, the EDA approach was further compared to a spatial interpolation method (kriging), and their advantages and disadvantages were discussed.

  2. Preparation of organic-inorganic hybrid silica monolith with octyl and sulfonic acid groups for capillary electrochromatograhpy and application in determination of theophylline and caffeine in beverage.

    PubMed

    Chen, Ming-Luan; Zheng, Ming-Ming; Feng, Yu-Qi

    2010-05-21

    An organic-inorganic hybrid silica monolithic column with octyl and sulfonic acid groups has been prepared by sol-gel technique for capillary electrochromatograhpy. The structure of hybrid monolith was optimized by changing the composition of tetraethoxysilane (TEOS), octyltriethoxysilane (C(8)-TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) in the mixture of precursors. Then, the obtained hybrid monolith was oxidized using hydrogen peroxide (30%, w/w) to yield sulfonic acid groups. The sulfonic acid group, which served as strong cation-exchanger, dominated the charge on the surface of the capillary column and generated stable electroosmotic flow (EOF) in a wide range of pH. The monolithic column was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and elemental analysis (EA), and the performance of column was evaluated in detail by separating different kinds of compounds with column efficiency up to 155,000 plates/m for thiourea. In addition, this monolithic column was also applied in the analysis of theophylline (TP) and caffeine (CA) in beverages. The detection limits were 0.39 and 0.48 microg/mL for theophylline and caffeine, respectively. The method reproducibility was tested by evaluating the intra- and inter-day precisions, and relative standard deviations of less than 3.9 and 8.4%, respectively, were obtained. Recoveries of compounds from spiked beverage samples ranged from 87.2 to 105.2%.

  3. Toxicity and DNA methylation changes induced by perfluorooctane sulfonate (PFOS) in sea urchin Glyptocidaris crenularis.

    PubMed

    Ding, Guanghui; Wang, Luyan; Zhang, Jing; Wei, Yuanyuan; Wei, Lie; Li, Yang; Shao, Mihua; Xiong, Deqi

    2015-06-01

    Perfluorooctane sulfonate (PFOS) is an ubiquitous persistent organic pollutant, which can be bioaccumulated and cause adverse effects on organisms. However, there is very limited information about the toxic effects of PFOS to marine organisms and its mechanisms. Therefore, in the present study, adult sea urchins Glyptocidaris crenularis were exposed to PFOS for 21 d, followed by a 7-d depuration period, in order to investigate the toxicity of PFOS to sea urchin and its potential epigenetic mechanisms. Sea urchins dropped spines, and lowered down the motor ability and feeding ability after the PFOS exposure. Superoxide dismutase activities in supernatant of coelomic fluid of sea urchin increased firstly and then dropped down, while the change of the catalase activity took an opposite trend during the exposure period. They both approached to the corresponding activity of the control after the depuration period. The DNA methylation polymorphism, methylation rate and demethylation rate in sea urchin gonad all increased following the prolonged exposure time, and then decreased after the depuration period. The demethylation rates were lower than the corresponding methylation rates, therefore methylation events were dominant during the whole experimental period. This might suggest that sea urchin have strong self-protection mechanisms and can survive from the PFOS exposure presented in this study. Further efforts are needed to more precisely investigate the DNA methylation effects of PFOS and the self-protection mechanism of sea urchin.

  4. Pretreatment of formula with sodium polystyrene sulfonate to reduce dietary potassium intake.

    PubMed

    Bunchman, T E; Wood, E G; Schenck, M H; Weaver, K A; Klein, B L; Lynch, R E

    1991-01-01

    Sodium polystyrene sulfonate (SPSS) is commonly administered for the acute and chronic treatment of hyperkalemia. Its oral intake is complicated by poor compliance due to multifaceted reasons. We therefore analyzed a method of reducing potassium (K) in formula by pretreatment with SPSS. If effective, this would bypass complications of enterally administered SPSS and provide low-K formula. Thirteen formulas and nutritional supplements were pretreated with SPSS to determine if one could bind K and provide formulas with decreased K contents. Using an SPSS concentration of 1 g/l mEq K in the formula, 62 +/- 2.6% (P less than 0.01, mean +/- SEM) of the K was removed in 30 min, while the sodium (Na) concentration was increased by 234 +/- 37% (P less than 0.01). Analysis suggests that the disproportionate increase in Na is due to exchange for calcium (Ca) and magnesium (Mg), interaction with proteins, and Na suspended with SPSS in the formula. Thus, SPSS pretreatment of formula is an effective method of making low-K formula, but the increase in Na exceeds the K reduction. Attention to possible complications of increased Na intake as well as decreased Ca and Mg intake is warranted.

  5. Spontaneous modification of graphite anode by anthraquinone-2-sulfonic acid for microbial fuel cells.

    PubMed

    Tang, Xinhua; Li, Haoran; Du, Zhuwei; Ng, How Yong

    2014-07-01

    In this study, anthraquinone-2-sulfonic acid (AQS), an electron transfer mediator, was immobilized onto graphite felt surface via spontaneous reduction of the in situ generated AQS diazonium cations. Cyclic voltammetry (CV) and energy dispersive spectrometry (EDS) characterizations of AQS modified graphite demonstrated that AQS was covalently grafted onto the graphite surface. The modified graphite, with a surface AQS concentration of 5.37 ± 1.15 × 10(-9)mol/cm(2), exhibited good electrochemical activity and high stability. The midpoint potential of the modified graphite was about -0.248 V (vs. normal hydrogen electrode, NHE), indicating that electrons could be easily transferred from NADH in bacteria to the electrode. AQS modified anode in MFCs increased the maximum power density from 967 ± 33 mW/m(2) to 1872 ± 42 mW/m(2). These results demonstrated that covalently modified AQS functioned as an electron transfer mediator to facilitate extracellular electron transfer from bacteria to electrode and significantly enhanced the power production in MFCs.

  6. Crystal structure of potassium (1S)-d-lyxit-1-yl­sulfonate monohydrate

    PubMed Central

    Haines, Alan H.; Hughes, David L.

    2015-01-01

    The title compound, K+·C5H11O8S−·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy­droxy­methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter­molecular O—H⋯O hydrogen bonding. PMID:26396774

  7. Crystal structure of potassium (1S)-d-lyxit-1-yl-sulfonate monohydrate.

    PubMed

    Haines, Alan H; Hughes, David L

    2015-08-01

    The title compound, K(+)·C5H11O8S(-)·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy-droxy-methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter-molecular O-H⋯O hydrogen bonding. PMID:26396774

  8. Toxicity and DNA methylation changes induced by perfluorooctane sulfonate (PFOS) in sea urchin Glyptocidaris crenularis.

    PubMed

    Ding, Guanghui; Wang, Luyan; Zhang, Jing; Wei, Yuanyuan; Wei, Lie; Li, Yang; Shao, Mihua; Xiong, Deqi

    2015-06-01

    Perfluorooctane sulfonate (PFOS) is an ubiquitous persistent organic pollutant, which can be bioaccumulated and cause adverse effects on organisms. However, there is very limited information about the toxic effects of PFOS to marine organisms and its mechanisms. Therefore, in the present study, adult sea urchins Glyptocidaris crenularis were exposed to PFOS for 21 d, followed by a 7-d depuration period, in order to investigate the toxicity of PFOS to sea urchin and its potential epigenetic mechanisms. Sea urchins dropped spines, and lowered down the motor ability and feeding ability after the PFOS exposure. Superoxide dismutase activities in supernatant of coelomic fluid of sea urchin increased firstly and then dropped down, while the change of the catalase activity took an opposite trend during the exposure period. They both approached to the corresponding activity of the control after the depuration period. The DNA methylation polymorphism, methylation rate and demethylation rate in sea urchin gonad all increased following the prolonged exposure time, and then decreased after the depuration period. The demethylation rates were lower than the corresponding methylation rates, therefore methylation events were dominant during the whole experimental period. This might suggest that sea urchin have strong self-protection mechanisms and can survive from the PFOS exposure presented in this study. Further efforts are needed to more precisely investigate the DNA methylation effects of PFOS and the self-protection mechanism of sea urchin. PMID:25723714

  9. Aquatic predicted no-effect-concentration derivation for perfluorooctane sulfonic acid.

    PubMed

    Qi, Ping; Wang, Ying; Mu, Jingli; Wang, Juying

    2011-04-01

    Perfluorooctane sulfonic acid (PFOS), a representative perfluorinated surfactant, is an anthropogenic pollutant detected in various environmental and biological matrices. Some laboratory and field work has been conducted to assess the aquatic toxicity of PFOS, but little is known regarding its toxicity threshold to the aquatic ecosystem. In the present study, predicted no-effect concentrations (PNECs) were derived by four different approaches. The interspecies correlation estimation (ICE) program and final acute-to-chronic ratio (FACR) were applied to the development of PNEC based on the toxic mode of action (MOA) of PFOS. By comparison of the different PNECs, the recommended aquatic toxicity thresholds for PFOS are in the range of 0.61 to 6.66 µg/L. Based on comparison of PNEC values, microcosm results, and reported environmental concentrations, PFOS appears not to pose a serious threat to aquatic organisms. The present results demonstrate that MOA is an important consideration for the derivation of reliable PNECs; moreover, the ICE-based species sensitivity distribution (SSD) method can be used to derive PNECs when toxicological data are limited. The application of MOA and ICE for deriving PNEC values in the present study may facilitate studies on using a combination of quantitative structure-activity relationship (QSAR) models and ICE to estimate PNECs.

  10. Synthesis of porous sulfonated carbon as a potential adsorbent for phenol wastewater.

    PubMed

    Prabhu, Azhagapillai; Al Shoaibi, Ahmed; Srinivasakannan, C

    2015-01-01

    The work reports a facile synthesis procedure for preparation of porous sulfonated carbons and its suitability for adsorption of phenol. The sulfonated carbon was synthesized utilizing a simplified, single-step, shorter duration process by sulfonation, dehydration and carbonization of sucrose in sulfuric acid and tetraethylorthosilicate. The surface and internal structures of the adsorbents were characterized utilizing various characterization techniques to understand the porous nature and surface functional groups of the porous matrix. Adsorption capacity was found to be highest for the sample heat treated at 600 °C, with the maximum adsorption capacity of 440 mg/g at 30 °C. The adsorption isotherms were tested with the Freundlich and Langmuir adsorption isotherms models to identify the appropriate adsorption mechanism.

  11. Sulfonated dyes attenuate the toxic effects of beta-amyloid in a structure-specific fashion.

    PubMed

    Pollack, S J; Sadler, I I; Hawtin, S R; Tailor, V J; Shearman, M S

    1995-09-15

    We recently reported that several sulfate-containing glycosaminoglycans, a class of compounds associated with the beta-amyloid plaques of Alzheimer's disease, attenuate the toxic effects of beta-amyloid fragments beta 25-35 and beta 1-40. The amyloid-binding sulfonated dye Congo Red was shown to have a similar effect. Using two clonal cell lines, we now demonstrate that several sulfonated dyes attenuate beta-amyloid toxicity and that the protective effect appears specific for compounds whose sulfonate groups can interact with the beta-pleated structure of aggregated amyloid. These results suggest that by binding beta-amyloid these compounds may prevent toxic interactions of the peptide with cells.

  12. QENS investigation of proton confined motions in hydrated perfluorinated sulfonic membranes and self-assembled surfactants

    NASA Astrophysics Data System (ADS)

    Berrod, Quentin; Lyonnard, Sandrine; Guillermo, Armel; Ollivier, Jacques; Frick, Bernhard; Gébel, Gérard

    2015-01-01

    We report on QuasiElastic Neutron Scattering (QENS) investigations of the dynamics of protons and water molecules confined in nanostructured perfluorinated sulfonic acid (PFSA) materials, namely a commercial Aquivion membrane and the perfluorooctane sulfonic acid (PFOS) surfactant. The former is used as electrolyte in low-temperature fuel cells, while the latter forms mesomorphous self-assembled phases in water. The dynamics was investigated as a function of the hydration level, in a wide time range by combining time-of-flight and backscattering incoherent QENS experiments. Analysis of the quasielastic broadening revealed for both systems the existence of localized translational diffusive motions, fast rotational motions and slow hopping of protons in the vicinity of the sulfonic charges. The characteristic times and diffusion coefficients have been found to exhibit a very similar behaviour in both membrane and surfactant structures. Our study provides a comprehensive picture of the proton motion mechanisms and the dynamics of confined water in model and real PFSA nanostructures.

  13. Mechanoassisted Synthesis of Sulfonated Covalent Organic Frameworks with High Intrinsic Proton Conductivity.

    PubMed

    Peng, Yongwu; Xu, Guodong; Hu, Zhigang; Cheng, Youdong; Chi, Chenglong; Yuan, Daqiang; Cheng, Hansong; Zhao, Dan

    2016-07-20

    It is challenging to introduce pendent sulfonic acid groups into modularly built crystalline porous frameworks for intrinsic proton conduction. Herein, we report the mechanoassisted synthesis of two sulfonated covalent organic frameworks (COFs) possessing one-dimensional nanoporous channels decorated with pendent sulfonic acid groups. These COFs exhibit high intrinsic proton conductivity as high as 3.96 × 10(-2) S cm(-1) with long-term stability at ambient temperature and 97% relative humidity (RH). In addition, they were blended with nonconductive polyvinylidene fluoride (PVDF) affording a series of mixed-matrix membranes (MMMs) with proton conductivity up to 1.58 × 10(-2) S cm(-1) and low activation energy of 0.21 eV suggesting the Grotthuss mechanism for proton conduction. Our study has demonstrated the high intrinsic proton conductivity of COFs shedding lights on their wide applications in proton exchange membranes.

  14. Mechanoassisted Synthesis of Sulfonated Covalent Organic Frameworks with High Intrinsic Proton Conductivity.

    PubMed

    Peng, Yongwu; Xu, Guodong; Hu, Zhigang; Cheng, Youdong; Chi, Chenglong; Yuan, Daqiang; Cheng, Hansong; Zhao, Dan

    2016-07-20

    It is challenging to introduce pendent sulfonic acid groups into modularly built crystalline porous frameworks for intrinsic proton conduction. Herein, we report the mechanoassisted synthesis of two sulfonated covalent organic frameworks (COFs) possessing one-dimensional nanoporous channels decorated with pendent sulfonic acid groups. These COFs exhibit high intrinsic proton conductivity as high as 3.96 × 10(-2) S cm(-1) with long-term stability at ambient temperature and 97% relative humidity (RH). In addition, they were blended with nonconductive polyvinylidene fluoride (PVDF) affording a series of mixed-matrix membranes (MMMs) with proton conductivity up to 1.58 × 10(-2) S cm(-1) and low activation energy of 0.21 eV suggesting the Grotthuss mechanism for proton conduction. Our study has demonstrated the high intrinsic proton conductivity of COFs shedding lights on their wide applications in proton exchange membranes. PMID:27385672

  15. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Structural evolution with hydration and heating

    SciTech Connect

    Sodeye, Akinbode; Huang, Tianzi; Gido, Samuel; Mays, Jimmy

    2011-01-01

    Small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS) have been used to study the structural changes in fluorinated polyisoprene/sulfonated polystyrene (FISS) diblock copolymers as they evolved from the dry state to the water swollen state. A dilation of the nanometer-scale hydrophilic domains has been observed as hydration increased, with greater dilation occurring in the more highly sulfonated samples or upon hydration at higher temperatures. Furthermore, a decrease in the order in these phase separated structures is observed upon swelling. The glass transition temperatures of the fluorinated blocks have been observed to decrease upon hydration of these materials, and at the highest hydration levels, differential scanning calorimetry (DSC) has shown the presence of tightly bound water. A precipitous drop in the mechanical integrity of the 50% sulfonated materials is also observed upon exceeding the glass transition temperature (Tg), as measured by dynamic mechanical analysis (DMA).

  16. Functionalization of overbased calcium sulfonates-synthesis and evaluation of antiwear and extreme-pressure performances

    SciTech Connect

    Delfort, B.; Born, M.; Daoudal, B.

    1995-12-01

    To improve antiwear and extreme-pressure performances of overbased calcium sulfonates, three overbased substrates with different colloidal characteristics were modified by partial neutralization with two sulfur-containing carboxylic acids, dithiodigylcolic acid and 4,4{prime} -(1,3,4-thiadiazole-2,5-diyl) bis (thiabutanoic) acid (DMTD/AA). In this way, six modified overbased calcium sulfonates were prepared. For each product, the colloidal nature of the calcium carboxylate was demonstrated, and all modified and non-modified compounds were evaluated as antiwear and extreme-pressure additives at different concentrations in oil in four-ball tests. The results of this evaluation show that the antiwear performances of basic overbased calcium sulfonates depends on the colloidal structure, while extreme-pressure properties depend on the total calcium carbonate amount in oil. Functionalization significantly enhances the extreme-pressure performances without affecting the initial good antiwear behavior. 20 refs., 9 figs., 4 tabs.

  17. Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments.

    PubMed

    Baena-Nogueras, Rosa María; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2013-05-01

    A new methodology has been developed for the determination of secondary alkane sulfonates (SAS), an anionic surfactant, in environmental matrices. Sediment and sludge samples were extracted using pressurized liquid extraction and sonication, whereas wastewater and surface water samples were processed using solid-phase extraction. Extraction recoveries were acceptable for both aqueous (78-120%) and solid samples (83-100%). Determination of SAS was carried out by high or ultra performance liquid chromatography - mass spectrometry using ion trap and time-of-flight detectors. The methodology was applied to samples from Guadalete River (SW Spain), where SAS concentrations below 1 μg L(-1) were measured in surface water, and from 72 to 9737 μg kg(-1) in sediments. Differential partitioning was observed for SAS homologues as those having a longer hydrocarbon chain which preferentially sorbed onto particulate matter. A preliminary environmental risk assessment also showed that SAS measured levels were not harmful to the aquatic community in the sampling area.

  18. Sulfonation of phenols extracted from the pyrolysis oil of oil palm shells for enhanced oil recovery.

    PubMed

    Awang, Mariyamni; Seng, Goh Meng

    2008-01-01

    The cost of chemicals prohibits many technically feasible enhanced oil recovery methods to be applied in oil fields. It is shown that by-products from oil palm processing can be a source of valuable chemicals. Analysis of the pyrolysis oil from oil palm shells, a by-product of the palm oil industry, reveals a complex mixture of mainly phenolic compounds, carboxylic acids, and aldehydes. The phenolic compounds were extracted from the pyrolysis oil by liquid-liquid extraction using alkali and an organic solvent and analyzed, indicating the presence of over 93% phenols and phenolic compounds. Simultaneous sulfonation and alkylation of the pyrolysis oil was carried out to produce surfactants for application in oil fields. The lowest measured surface tension and critical micelle concentration was 30.2 mNm(-1) and 0.22 wt%, respectively. Displacement tests showed that 7-14% of the original oil in place was recovered by using a combination of surfactants and xanthan (polymer) as additives.

  19. Highly efficient sulfonated polybenzimidazole as a proton exchange membrane for microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Singha, Shuvra; Jana, Tushar; Modestra, J. Annie; Naresh Kumar, A.; Mohan, S. Venkata

    2016-06-01

    Although microbial fuel cells (MFCs) represent a promising bio-energy technology with a dual advantage (i.e., electricity production and waste-water treatment), their low power densities and high installation costs are major impediments. To address these bottlenecks and replace highly expensive Nafion, which is a proton exchange membrane (PEM), the current study focuses for the first time on membranes made from an easily synthesizable and more economical oxy-polybenzimidazole (OPBI) and its sulfonated analogue (S-OPBI) as alternate PEMs in single-chambered MFCs. The S-OPBI membrane exhibits better properties, with high water uptake, ion exchange capacity (IEC) and proton conductivity and a comparatively smaller degree of swelling compared to Nafion. The membrane morphology is characterized by atomic force microscopy, and the bright and dark regions of the S-OPBI membrane reveals the formation of ionic domains in the matrix, forming continuous water nanochannels when doped with water. These water-filled nanochannels are responsible for faster proton conduction in S-OPBI than in Nafion; therefore, the power output in the MFC with S-OPBI as the PEM is higher than in other MFCs. The open circuit voltage (460 mV), current generation (2.27 mA) and power density profile (110 mW/m2) as a function of time, as well as the polarization curves, exhibits higher current and power density (87.8 mW/m2) with S-OPBI compared to Nafion as the PEM.

  20. Toxicokinetics of seven perfluoroalkyl sulfonic and carboxylic acids in pigs fed a contaminated diet.

    PubMed

    Numata, Jorge; Kowalczyk, Janine; Adolphs, Julian; Ehlers, Susan; Schafft, Helmut; Fuerst, Peter; Müller-Graf, Christine; Lahrssen-Wiederholt, Monika; Greiner, Matthias

    2014-07-16

    The transfer of a mixture of perfluoroalkyl acids (PFAAs) from contaminated feed into the edible tissues of 24 fattening pigs was investigated. Four perfluoroalkyl sulfonic (PFSAs) and three perfluoroalkyl carboxylic acids (PFCAs) were quantifiable in feed, plasma, edible tissues, and urine. As percentages of unexcreted PFAA, the substances accumulated in plasma (up to 51%), fat, and muscle tissues (collectively, meat 40-49%), liver (under 7%), and kidney (under 2%) for most substances. An exception was perfluorooctanesulfonic acid (PFOS), with lower affinity for plasma (23%) and higher for liver (35%). A toxicokinetic model is developed to quantify the absorption, distribution, and excretion of PFAAs and to calculate elimination half-lives. Perfluorohexanoic acid (PFHxA), a PFCA, had the shortest half-life at 4.1 days. PFSAs are eliminated more slowly (e.g., half-life of 634 days for PFOS). PFAAs in pigs exhibit longer elimination half-lives than in most organisms reported in the literature, but still shorter than in humans.